Start the ragù magic — Heat olive oil in a large pot over medium heat. Add onion, carrot, celery, and garlic—sauté gently for 8-10 minutes until soft and fragrant. This soffritto builds incredible flavor!
Brown the meat — Crumble in the ground beef, season with salt and pepper, and cook until browned (about 10 minutes). Break it up as it cooks for even texture.
Add depth — Pour in red wine and let it bubble away for 5 minutes to reduce. Stir in tomato paste, then passata, broth, bay leaf, and nutmeg. Bring to a simmer, then lower heat and cook uncovered for 2-3 hours, stirring occasionally. Taste and adjust seasoning—your kitchen will smell heavenly!
Whip up silky béchamel — In a saucepan, melt butter over medium heat. Whisk in flour and cook 1-2 minutes (no browning!). Slowly add milk while whisking constantly to avoid lumps. Simmer until thick (5-8 minutes), then season with nutmeg, salt, and pepper. Set aside—it's creamy perfection!
Prep the oven — Preheat to 375°F (190°C). Lightly grease a 9x13-inch baking dish.
First layer love — Spread a thin layer of ragù on the bottom. Add 3-4 lasagna sheets (trim to fit).
Layer like a pro — Spoon over ragù, then béchamel, and sprinkle generously with Parmigiano. Repeat layers (pasta, ragù, béchamel, cheese) 3-4 times, ending with béchamel and extra Parmigiano on top.
Top it off — For extra gooeyness, add mozzarella if desired. Cover with foil.
Bake to bubbly bliss — Bake covered for 25 minutes, then uncover for 15-20 minutes until golden and bubbling.
Rest and serve — Let it rest 15-20 minutes (patience pays off!). Slice and enjoy every creamy, meaty bite!