Wash the potatoes and cook in boiling water for about 25 minutes. Stir 300 g quark and yoghurt until smooth. Season to taste with salt and pepper. Wash chives, shake dry and cut into small rolls.
Fold the chive rolls, up to 1 tablespoon, into the quark. Wash and halve the tomatoes. Peel and finely chop the onion. Season lemon juice with salt, pepper and sugar, fold in 2 tablespoons of oil.
Stir in the remaining chive rolls. Mix with the tomatoes. Drain the potatoes, peel and press them through the potato ricer into a bowl and let them cool down a little. Add egg yolk, 200 g quark and flour and mix.
Season with salt, pepper and nutmeg. Heat 4-5 tablespoons of oil in portions in a pan. Fry 12 small lentils from the potato dough at medium heat in portions. Arrange the lentils with chive dip and tomato salad.