Lamb cutlets with onion sauce

1) Arrange the lamb cutlets on a grill pan.
2) Grill for 15 minutes, turning occasionally, until well cooked with the fat crisp in places.
3) Meanwhile, peel and chop the onions.
4) Melt the butter in a frying pan and fry the onions gently for 10 minutes, while the cutlets cook.
5) Stir in the flour and cook for 1 minute, then gradually stir in the stock and bring the sauce to the boil. Simmer for 2 minutes, stirring occasionally.
6) Season well and serve with the cutlets and some mashed potato.