Cook spinach in 100 ml boiling salted water for about 15 minutes over medium heat. In the meantime, beat the fat until foamy, stir in the eggs bit by bit and season with salt, pepper and nutmeg.
Stir in flour and milk and let it swell for about 15 minutes. Drain the spinach. Wash the cucumber and grate roughly. Peel garlic and press it through a garlic press. Mix quark and yoghurt.
Add cucumber and garlic and season with salt and pepper. Preheat a waffle iron and grease it a bit. Mix spinach into the waffle batter and put 2-3 tablespoons of batter into the waffle iron.
Bake for about 3 minutes until golden brown, remove and keep warm. Bake the rest of the waffles in the same way. Clean, wash and quarter the tomatoes. Peel and finely chop the onion. Mix vinegar, sugar, salt and pepper and add the oil.
Mix the tomatoes and onion and pour the vinaigrette over it. Serve garnished with parsley.