1-First: preheat the oven to 190°C and boil the 190 grams of elbow macaroni in salted water until al dente, then drain and set aside. In a skillet, heat the 30 milliliters of olive oil over medium heat, sauté the 1 chopped onion until translucent, add the 3 minced garlic cloves and cook for one minute, then add the 450 grams of ground beef and brown it fully, stirring in the 240 milliliters of barbecue sauce and simmering for five minutes.

2-Next: in a separate saucepan, melt the 43 grams of unsalted butter over medium heat, stir in the 16 grams of all-purpose flour to form a roux, and cook for one minute. Gradually whisk in the 240 milliliters of whole milk, stirring until the sauce thickens, and season with the 5 grams of fine sea salt and 1 gram of ground black pepper. Add the 200 grams of shredded cheddar cheese and half of the 200 grams of shredded mozzarella cheese, stirring until melted and smooth, then toss the cooked elbow macaroni in this cheese sauce.

3-Cook: the 8 lasagna noodles in boiling salted water until al dente, then drain. Grease a 23 x 33 cm baking dish and layer the noodles, half of the meat mixture, half of the mac and cheese mixture, and sprinkle with part of the remaining shredded mozzarella cheese; repeat the layers, finishing with the rest of the mozzarella cheese.

4-Baking and Serving: Cover the dish with foil and bake for 25 minutes, then remove the foil and bake for an additional 10 minutes until the cheese is golden and bubbly. Let the dish stand before slicing, garnish with the fresh chopped parsley, and serve warm. This method ensures the layers stay intact and flavors meld perfectly.