Preheat an oven to 200°c/180°c fan (392°f/356°f).
Cut the carrots on an angle, into 1½" - 2" pieces then place into a roasting tin.
Drizzle over the veg oil then season the carrots with salt & pepper & stir to coat.
Roast the carrots for 25-30 minutes, until they are soft but still slightly undercooked, making sure to stir/shake the tin every 10-15 minutes.
In the meantime, place the marmalade, butter & thyme into a saucepan then cook over a low heat until melted.
Next, pour the marmalade & butter over the carrots & stir to coat. Roast for another 10-15 minutes, until nicely caramelised & tender.
To finish, sprinkle over the chopped parsley & season with salt & pepper. Serve immediately.