Peel, wash and grate the potatoes. Peel onions. Grate 1 onion with the potatoes. Stir in 2 eggs and starch well. Season with salt and pepper
Dice the remaining onion. Knead with minced meat and 1 egg. Seasoning
Heat a square waffle iron, alternatively a pan, and spread with oil. Bake 8 waffles or buffers from the potato dough one after the other, keep warm. Divide the minced meat into 4 portions. Fry in the waffle iron or pan for 3-4 minutes each
Clean the lettuce and tomatoes. Cut cress from the bed. Wash everything. Cut the tomatoes into slices. Stir tartar sauce and yoghurt until smooth. Stir in half the cress.
Cover 4 wafers with 1 lettuce leaf, 1 minced steak, tomatoes and tartar sauce. Cover with remaining waffles and garnish with remaining cress