Heat 1 tablespoon of olive oil in a large casserole dish. Fry guinea fowl legs on both side, remove from casserole and reserve.
Peel onions. Brown bacons for 3 minutes, add onions and leave to cook for 3 minutes.
Add guinea fowl legs, white wine, chicken stock and pepper.
Cover and leave to cook on medium/low heat for 50 minutes.
Add chestnuts and cook for another 10 minutes.
Remove meat and vegetables from casserole dish.
Spread some ciselled chervil and serve.