Preheat the stove to 6/fan180C 200C / Gas. Squeeze the juice from 2 lemons into a tiny pan and heat with butter, honey, rosemary, garlic and salt and pepper until the butter melts and smells fragrant.
Lay the chicken in a roasting tin–don’t pile it or it won’t cook so well. Add the potatoes and sprinkle with lemon butter to coat uniformly. Cut the third lemon into eight wedges and insert them in. (Can be produced up to 2 hours before this stage.)