Pre-heat the oven to 220c.
Peel and halve the carrots, boil in salted water for 10 mins.
In a flat oven dish, coat the onions & garlic in the olive oil, cumin seeds & ground cumin, generously season with salt & pepper. Drain the cooked carrots and add to the dish and cover with oil.
Roast for 50 mins, turning over the carrots half way through.
Remove from the oven and cool the carrots in a bowl, with 50g of butter. Leave to cool completely. Add fresh parsley.