Wash the chicken filet. Peel and slice the onion. Clean, wash and cut the carrot into large pieces. Bring stock, wine, onion, carrot and peppercorns to the boil, add meat and simmer at low heat for about 20 minutes. In the meantime drain the tuna.
Put tuna, salad cream and cream in a mixing bowl and puree with a hand blender. Season to taste with salt and pepper and stir in half the capers. Clean, wash, quarter and dice the tomato. Clean, wash and halve cherry tomatoes. Clean, wash, dab dry and cut into large pieces. Mix vinegar, salt, sugar and pepper. Whip oil into it. Take the chicken filet out of the stock and cut it thinly. Arrange meat and salad on a plate.
Mix vinegar, salt, sugar and pepper. Whip oil into it. Take the chicken filet out of the stock and cut it thinly. Arrange meat and salad on a plate. Pour tuna sauce over the meat and sprinkle with tomatoes, remaining capers and pepper. Serve garnished with lemon wedges as desired