Cook the lasagne sheets in plenty of salted water according to the package instructions. Quench in ice water and let it drip off. Clean and wash the spinach. Peel and finely dice shallots and garlic cloves
Heat oil in a large pan, sauté diced shallots and garlic in it, add spinach and let it collapse while stirring. Season with salt, pepper and nutmeg, place on a sieve and squeeze gently
Grate mountain cheese. Stir cream cheese, mountain cheese and milk until smooth. Wash thyme, shake dry and chop leaves coarsely and stir in. Season cheese cream with salt and pepper. Wash, clean and slice the tomatoes
Spread out a casserole dish. Spread a thin layer of sauce, then lasagne sheets, tomato slices, some spinach and cheese cream on top. Repeat the process, finishing with a layer of pasta
Grate parmesan. Sprinkle the lasagne with parmesan, spread the remaining butter in small pieces on top. Bake on the middle shelf for about ten minutes until golden brown