Wash the chilli pepper, cut into rings and remove the seeds. Wash lemons hot, peel the peel of 1 lemon thinly and cut into fine strips. Squeeze the juice. Wash the herbs and finely chop 1/3 each of the rosemary and parsley.
Peel and finely chop the garlic. Mix prepared ingredients and oil. Wash leg of lamb, dab dry, rub with salt and the herb-oil-lemon mixture. Place the leg of lamb in the fat pan of the oven.
Roast in the preheated oven (electric cooker: 200 °C / gas: level 3) for approx. 2 hours. Drain the tomatoes and collect the juice. Pour tomato juice and some stock into the meat after about 30 minutes.
Gradually pour on the remaining stock and add the stock to the drumstick from time to time. Peel and wash the potatoes and cut them lengthwise into slices. Clean, wash and halve the mushrooms. Cut the rest of the lemon into narrow slices.
Peel the shallots and, depending on the size, halve or quarter them. Coarsely dice peeled tomatoes and chop the remaining herbs coarsely, except for some parsley. Add the prepared ingredients to the leg of lamb about 45 minutes before the end of the cooking time.
Sprinkle with salt and pepper and braise as well. Cover the leg if necessary so that it does not get too dark. Season the vegetables to taste. Garnish with parsley and serve sprinkled with lemon pepper.