Wash the meat and dab dry. Heat the oil in a coated pan and fry the meat in it from both sides for about 5 minutes each. Season with salt, pepper and paprika. Wash the thyme, dab dry and chop finely.
Sprinkle over the meat just before the end of the frying time. In the meantime, cut off a lid from each tomato and hollow out the tomatoes. Cut the tomato lids into small cubes. Clean, wash and roughly grate the cucumber.
Mix curd and milk and season with salt and pepper. Peel garlic and press it through a garlic press. Squeeze the cucumber a little bit and add it together with the garlic to the quark and stir in.
Fill tomatoes with tzatziki. Cut the chicken filet into slices and arrange on a plate together with the stuffed tomatoes. Sprinkle with tomato cubes and serve garnished with lettuce leaves as desired.