Rinse chicken legs and pat dry, then cut each leg at the joint to separate thighs and drumsticks. Rinse bell peppers and remove seeds and cores, cut into 5-7 cm pieces. Rinse zucchini and eggplant, cut into 5-7 cm pieces. Rinse tomatoes and cut into wedges. Peel red onions and cut into wedges. Peel and rinse potatoes, quarter them. Mince the garlic cloves or leave whole. Rinse lemon and cut into wedges.
Mix quark and sour cream together in a bowl, then stir in mixed herbs, chilli flakes, and pepper to taste. Cover and refrigerate the dip (can be made several hours ahead).
Arrange potatoes in a large baking dish, then layer peppers, zucchini, eggplant, tomatoes, and onions on top. Scatter lemon wedges and garlic cloves over vegetables. Place chicken pieces on top. Sprinkle with roughly equal amounts of thyme, rosemary, and basil to taste. Season with pepper and Vegeta or salt to taste. Drizzle generously with olive oil.
Bake uncovered at 170°C (338°F) for 45 minutes, until chicken is golden brown and the thickest part reaches 74°C (165°F).
Remove from oven and serve hot with the herb dip on the side. Garnish with fresh parsley.