guinea fowl is delicious in curry or casserole. So much better than chicken - they have a lovely thin layer of yellow subcutaneous fat, which is not as excessive as you would find on duck, but tastier than chicken.
Any kind of home made curry (made from scratch, not with a prepared paste or sauce) will be delicious.
I usually make guinea fowl tagine - basically joint the bird and coat it in ras el hanout, then brown with a chopped onion, garlic, then add a can of tomatoes, saffron, chicken stock, cinnamon stick, and cook for an hour and a half in a moderate oven. (You can potentially add lots of things to the casserole according to your taste, carrots, olives, preserved lemons, etc.)
You can of course make your own ras el hanout blend.
I would serve with couscous, coooked in chicken stock, and then either half a jar of tomato passata, some roasted vegetables (courgettes, red onion, aubergines), and coriander leaf, or toasted flaked almonds, raisins and olive oil.
Would not recommmend roasting them.