Leftover Roast Potato Burger Buns
Here’s how to turn leftover roast potatoes into a batch of homemade burger buns! These are soft & fluffy and perfect for a roast beef sandwich.
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A potato burger bun is easily one of my favourite types of bread & is my go to bun of choice whenever I cook burgers! They’re soft & fluffy yet robust enough to hold up to the juiciest burger. Plus, they’re even more flavourful than your regular bun!
So this recipe came about because I was looking for a way to use up some roast potatoes that I had leftover from a Sunday roast dinner. I’ve made potato burger buns before (in fact it’s one of my most popular recipes!) but normally I would use regular mashed potatoes. The concept for these buns is the same, except we’re swapping out the mash for leftover roast potatoes that are cooked down in milk to soften then mashed through a potato ricer & used in the dough.
I’ve also slightly increased the dough weight per bun for this batch. The idea for these buns is to fill them with whatever roasted meat you have leftover from your Sunday roast, so we’re making them slightly bigger to accommodate this. Slices of beef, pork or lamb do tend to be a bit wider than your average burger!
For more burgers buns, loafs of bread, sourdough, muffins, flatbreads & more, check out our ever growing collection of bread recipes!
What You’ll Need
- Leftover Roast Potatoes – For 6 buns, you’ll need 150 grams of leftover roast potatoes, which is roughly 3 or 4 large roast potatoes. I used my goose fat roast potatoes but any roasties from a Sunday roast dinner will work.
- Bread Flour – Make sure to use a strong white bread flour with a protein content between 12-14%. I use a Canadian white bread flour from Shipton Mill.
- Yeast – Either dried active yeast or instant yeast will work for these buns. Dried active yeast needs to be activated in warm liquid whereas instant yeast can be added directly into the flour. Using instant yeast will also speed up the proving time slightly.
- Salt – A good quality sea salt works best when making bread.
- Sugar – Adding a small amount of caster sugar to bread dough gives bread a softer, more tender crumb & a deep golden colour.
- Milk Powder – Adding a small amount of milk powder into the dough helps give the buns a deeper golden colour once baked. Adding this in is optional though, so don’t worry if you haven’t got any.
- Butter – We’re adding butter into the dough & brushing it on top of the buns once they’re baked, to give them a glossy finish. Make sure to use unsalted butter, as this lets us control the salt content of the dough.
- Egg – You’ll need a large egg for the dough & another for the egg wash. A large egg should weigh around 50 grams out of the shell.
- Sesame Seeds – Topping your burger buns with sesame seeds is optional but I like the added crunch & colour that they give. I used a 50/50 mix of black & white sesame seeds.
How To Use Leftover Roast Potatoes To Make Bread
I’m a huge fan of using mashed potatoes in bread dough, as it makes bread that’s more flavourful, softer & fluffier (thanks to the added moisture from the potatoes). Adding mash to bread dough also increases the hydration percentage without making the dough difficult to work with!
Now usually when I make potato bread dough, I roast the potatoes whole then scoop the mash out of the skins (I also chop up the crispy skins & add them in as well!). However, when you use leftover roast potatoes from a Sunday roast, they’re already cooked! But in order to mash them, we need to chop them up then cook in a pan with a splash of milk to soften them up enough to mash through a potato ricer. Other than that, the process is pretty much exactly the same as my regular potato burger buns.
Recipe Breakdown
- Roast Potato Mash
Chop the roast potatoes into small chunks, add into a pan with milk then cook over a low heat until the liquid has reduced & the potatoes are soft. Once cooked, mash the potatoes then leave to cool to room temperature. - Bread Dough
Make the dough by mixing bread flour with sugar, salt, yeast, milk powder, an egg, milk, water & the mashed potato. Mix in a stand mixer until smooth then gradually add in softened butter. Continue mixing until the dough passes the windowpane test (another 5 minutes or so). - First Rise
When the dough’s ready, let it rise at room temperature until it has doubled in size. This will take 45 minutes – 1 hour. - Shaping
Once risen, knock the dough back, divide into 6 equal pieces then shape into balls. Place the buns onto a lined baking tray, making sure to space them well apart to give them plenty of room to rise. - Second Rise
Next, cover the tray of buns with an upside down roasting tin (or loosely with clingfilm) then leave to prove at room temperature until they have doubled in size. This will take another 30-45 minutes. - Egg Wash
Before baking the buns, we make an egg wash by whisking an egg & a teaspoon of water together in a small bowl. We then brush each bun with a generous amount of the egg wash then top with a sprinkle of sesame seeds. - Baking
We bake the buns at 180°c/356°f for 20-25 minutes until they have risen & are a deep golden brown. As soon as they come out of the oven, we brush each bun with melted butter then leave to cool on the tray.
The windowpane test is where you stretch a small amount of dough between your fingers. If the dough stretches thin enough to see through, proper gluten development has been achieved. If the dough tears, it needs to be mixed for longer.
Serving Suggestions
These roast potato burger buns are designed to use up leftovers from a Sunday roast dinner! So the potatoes are used in the bread dough & any leftover meat & gravy can be used for the filling. I filled my burger buns with thinly sliced roast beef that I reheated in gravy, plus some Swiss cheese & a generous amount of horseradish sauce. You could also make a roast pork & apple sauce sandwich or a chicken sandwich with cranberry sauce & stuffing. You get the idea!
Frequently Asked Questions
To bake burger buns in an Aga, cook them in the baking oven on the bottom set of runners.
Yes, in order to properly develop the gluten in the dough, you’ll need to use a stand mixer to make potato burger buns.
Floury varieties of potatoes are best for roasting as they are less starchy & contain less moisture, so make roast potatoes that are fluffy on the inside & crisp on the outside. I use Maris Piper potatoes but Russets & King Edward’s will work as well.
Yes, regular mashed potatoes can be used to make burger buns. It’s best to roast the potatoes whole then scoop the mash out of the skins (instead of boiling them), to avoid adding too much moisture to the dough. If you’d like to make regular potato burger buns, check out my potato burger bun recipe!
Potato burger buns will keep for up to 3 days when stored in an airtight container at room temperature. To get a few days extra shelf life, the buns can be stored in the fridge then brought back up to room temperature to serve. Or you could cut them in half & toast them straight from the fridge.
Equipment Used
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More Bread Recipes To Try!
- Potato Sandwich Bread
- Baked Camembert Dough Ball Wreath
- Tangzhong Dinner Rolls
- Same Day Focaccia
- 3 Day Poolish Pizza Dough
- Tear And Share Cheesy Garlic Bread
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Leftover Roast Potato Burger Buns
Equipment
- Stand Mixer
- Digital Food Probe
- Saucepan
- Potato Ricer
- Baking Tray
Ingredients
Roast Potato Mash
- 150 g Leftover Roast Potatoes (See Notes)
- 150 g Whole Milk
Dough
- 350 g Strong White Bread Flour
- 80 g Whole Milk
- 50 g Water
- 6 g Dried Active Yeast
- 7 g Fine Sea Salt
- 15 g Caster Sugar
- 1 tsp Skimmed Milk Powder
- 1 Large Egg (50g Out Of The Shell)
- 35 g Unsalted Butter (Room Temperature)
Egg Wash
- 1 Egg
- 1 tsp Cold Water
To Finish
- 2 tsp Sesame Seeds (White, Black Or A Mix Of Both)
- 25 g Melted Unsalted Butter
Instructions
Roast Potato Mash
- Chop the roast potatoes into 2cm pieces then add into a small saucepan with the milk. Cover the pan with a lid then set over a low heat.
- Cook the potatoes, stirring occasionally until the liquid has reduced completely & the potatoes are soft. This will take 5-10 minutes.
- Once cooked, use a potato ricer to mash the potatoes then weigh out 200 grams of mash & leave to cool to room temperature.This should be all of the potatoes! It's best to weigh the mash out though to make the dough accurately.
Dough
- Place the milk & water into a jug & warm in the microwave to 38°c/100°f (alternatively you could heat this up in a saucepan then transfer to a jug), then whisk in the yeast & leave to go bubbly. This will take 5-10 minutes.
- Next, add the flour, mashed potato, salt, sugar, milk powder & egg into the bowl of a stand mixer. Give the activated yeast another whisk then add into the flour.
- Using the dough hook, knead the dough on a medium speed until smooth & starting to come away from the sides of the bowl. This will take around 5 minutes.
- With the mixer still going, add in the soft butter a small amount at a time, incorporating each piece fully before adding more. Once all the butter has been incorporated, keep mixing until the dough passes the window pane test. This will take another 5-10 minutes.To perform the windowpane test, stretch a small amount of dough between your fingers. If the dough stretches thin enough to see through, it's ready. If it doesn't, it needs more mixing.
- Once the dough is ready, cover the bowl with clingfilm (or a tea towel) then let it prove at room temperature until it has doubled in size. This will take 45 minutes – 1 hour.
Shaping
- Once risen, knock the dough back then transfer it to a lightly floured surface. Then use a bench scraper to divide the dough into 6 equal pieces. Each should weigh around 130 grams.
- To shape, take a piece of dough & bring the edges into the middle. Flip the dough over & use cupped hands to shape into a tight ball. Dragging the seam on the work surface helps increase surface tension.
- Transfer the shaped bun to a lined baking tray then repeat the shaping process with the remaining pieces of dough. Make sure to place the buns spaced apart on the tray, so that they have room to rise.
- Once shaped, lightly press each bun down with your fingers then cover the tray with a roasting tin (flipped upside down) or loosely with oiled clingfilm. Leave to double in size at room temperature. This will take 30 – 45 minutes.Pressing the buns down slightly helps them rise more evenly. If you don't I find that the buns can peak on top once baked.
- In the meantime, preheat an oven to 180°c/160°c fan (356°f/320°f).
Baking
- Once the buns have risen, make the egg wash by adding the egg & water into a small bowl then whisk together. Brush each bun with a generous amount of the egg wash then top with a sprinkle of sesame seeds.
- Bake the buns in the preheated oven for 20-25 minutes, until they have risen & are a deep, golden brown.
- As soon as the buns come out of the oven, brush each one with a generous amount of melted butter then leave to cool completely on the tray.Melt the butter whilst the buns are baking, so that it's still warm when you brush it on!
