For the lemon chicken, first peel and coarsely dice the onion. Wash and finely chop the carrot. Wash and coarsely chop the kohlrabi and zucchini. Peel the potatoes and also cut them roughly. Cut the tomatoes in half and cut out the stalk. Finely slice the ginger with the peel. Cut the garlic bulb in half. Rub the lemons with warm water and cut them in half. Divide the chicken into 4 breast and 4 knuckle pieces. Remove the bones from the knuckles.
Preheat the oven to 180 °C.
In a large frying pan, brown the chicken pieces on all sides in half of the oil and season with salt and pepper. Place on a baking sheet with the skin side up.
In the same pan, sauté the vegetables (except the tomatoes), season with salt and pepper and place between the chicken pieces. Add the tomatoes. Squeeze a little juice over them from the halved lemons, then slice the lemon halves and add to the vegetables. Finally, add the thyme, rosemary, garlic and the remaining olive oil.
Put the lemon chicken in the oven for about 60 minutes.