Chicken and Mushroom Casserole

4 - 6 oz. (175g) skinless chicken pieces
6 oz. (175g) mushrooms, wiped and trimmed
8 fl. oz. (250ml) chicken stock
1 oz. (25g) chopped onion
salt to taste
freshly ground black pepper

Pre-heat oven to 425F, Gas Mark 7, 220C
Place the chicken pieces in a casserole with sliced mushrooms
Add the stock, onion, salt and pepper
Cover and cook in the pre-heated oven for 40 minutes, or until the chicken is tender
Serve while the chicken is still hot