Peel and finely dice the onions. Peel garlic and chop finely. Heat 2 tablespoons of oil in a pot, fry half of the onions and 2/5 of the garlic in it. Add 2 tbsp. tomato paste, sauté and deglaze with tomatoes. Season with salt, pepper, sugar and paprika
Bring to the boil and simmer for about 5 minutes. Wash and drain the tomatoes. Add the tomatoes to the sauce, bring to the boil again briefly and season to taste
Heat 2 tablespoons of oil in a frying pan, crumble the minced meat into it and fry vigorously while turning. Add remaining onions and 2/5 of the garlic and fry briefly. Season with salt, pepper and paprika. Stir in 2 tablespoons of tomato puree, sauté briefly. Deglaze with broth, simmer for 2-3 minutes
Dab feta dry and cut into very thin slices. Pour a little sauce into an ovenproof dish (26.5 x 19 x 6.5 cm) and distribute evenly. Place 3 lasagne sheets next to each other on top of the dish, alternating layers of minced meat, sauce and feta. Layer the remaining ingredients in the same way, finish with tomato sauce
Drain mozzarella cheese well and cut into slices. Cover lasagne evenly with it. Bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 1 hour
For the sauce, wash baby spinach and drain well. Place the spinach, remaining garlic and 2 tbsp. oil in a tall mixing bowl and puree finely with a hand blender. Add crème fraiche. Season to taste with salt and pepper. Take the lasagne out of the oven, add a pinch of spinach sauce and garnish with spinach leaves as desired