1. Sauté minced garlic cloves and sliced onions in a little olive oil.
2. Add chopped carrot and celery stalk, then the meat, and sauté everything.
3. After a few minutes, add red wine. Cook until it evaporates.
4. Add tomato puree, water, and herbs.
Season with salt and pepper, then simmer over low heat for 45 minutes.
5. Prepare the béchamel sauce: melt 100g of butter (reserve the rest for topping).
6. Off the heat, add the flour all at once.
7. Return to heat and whisk until the mixture becomes smooth.
8. Gradually add the milk.
9. Stir constantly until the mixture thickens.
10. Then, season with nutmeg, salt, and pepper. Let it cook for about 5 minutes over very low heat, stirring occasionally. Set aside.
11. Preheat the oven to 200°C (thermostat 6-7).
Grease the lasagna dish. Place a thin layer of béchamel sauce, then lasagna sheets, bolognese sauce, béchamel sauce, and parmesan cheese.
Repeat the process 3 times.
12. On the last layer of lasagna sheets, only add béchamel sauce and cover with grated cheese. Sprinkle a few knobs of butter.
13. Bake for about 25 minutes.
14. Enjoy!