For the seasoning butter, wash lemons hot and grate them dry. Finely grate the zest of 1 lemon and squeeze the juice of the lemon. Cut the remaining lemon into slices. Peel and finely chop the garlic cloves. Mix 150 g butter, salt, pepper, garlic, lemon peel and juice.
For the chicken, wash the rosemary and pluck roughly. Cut the garlic bulb in half crosswise. Cut the chicken open at the back, wash thoroughly and pat dry. Cut the sternum so far that the chicken can be laid flat.
Spread rosemary and lemon slices on the fat pan. Spread chicken on both sides with seasoning butter. Place the skin side up on the rosemary and lemon bed. Spread garlic around the meat. Roast in the preheated oven (electric cooker: 200 °C/circulating air: 175 °C/gas: see manufacturer) for 1-1 1⁄4 hours.
For the vegetables, clean, wash and cut the beans into pieces and simmer in little boiling salted water for 6-8 minutes. Peel onions and cut into slices. Heat 2 tablespoons of butter in a large deep frying pan. Sauté the onions until translucent. Drain the beans, let them drain and toss them. Arrange everything. Baguette tastes good with it.