Peel, wash and halve the potatoes. Cook in salted water for about 20 minutes
Clean, wash and slice the aubergines lengthwise in approx. 1/2 cm thin slices. Salt lightly and leave to stand for about 10 minutes
Peel and finely chop the onion. Fry in 1 tbsp. hot oil. Deglaze with tomatoes and juice. Chop the tomatoes coarsely. Add bay leaf, simmer for about 20 minutes
Peel the garlic and press through. Drain potatoes and mash finely. Stir in milk, garlic, 2-3 tablespoons of oil and parmesan. Season to taste with salt and pepper.
Dab aubergines. Fry in 2 tablespoons of hot oil in portions on each side until golden brown. Remove. Place 2 slices crosswise on top of each other. Place 2 tablespoons of puree in the middle of each slice. Whip the aubergine slices into a packet and fold over the mixture
Season tomato sauce to taste and pour into a flat ovenproof dish. Place aubergine parcels on top. Cut the mozzarella into slices and place on top. Bake in the preheated oven (electric cooker: 225 °C/circulating air: 220 °C/gas: level 4) for approx. 10 minutes
Wash the thyme, remove the leaves. Roast pine nuts without fat. Sprinkle both over the aubergines before serving