1 Pat the chicken pieces dry. Using a knife, make two or three deep incisions through the skin and flesh to the bone of each piece. Season the chicken generously with salt and pepper.
Melt the butter and oil in a heavy-bottomed pan with a tight-fitting lid and fry the chicken pieces until well browned all over (about 10 minutes). Remove from the pan.
2 Using the same pan, sauté the onions for a few minutes; add a splash of water to the pan, then cook a little longer until the liquid has cooked off – this will allow the onions to soften before they start to brown. Remove the onions; set aside with the chicken, then fry the chopped mushrooms. Add an extra dash of oil to brown the mushrooms, if necessary.