Instructions:
- Phase 1: The Ragù. Heat oil in a large Dutch oven. Add onion, carrot, and celery. Cook gently until softened (about 8-10 minutes). Add garlic and cook for 1 minute more.
- Increase heat. Add ground beef and pork. Cook, breaking up the meat, until well-browned. Drain off any excess fat.
- Pour in red wine. Scrape up any browned bits from the bottom of the pot. Let the wine reduce by half.
- Stir in tomato paste, crushed tomatoes, stock, bay leaf, oregano, salt, and pepper. Bring to a gentle simmer.
- Reduce heat to low, cover loosely, and simmer for at least 90 minutes (preferably 2 hours), stirring occasionally, until the sauce is thick and rich. Remove bay leaf.
- Phase 2: The Béchamel and Pasta Prep. If using standard noodles, boil until al dente, drain, and lay flat on parchment paper. (Skip if using oven-ready).
- Make the Roux: Melt butter in a saucepan over medium heat. Whisk in the flour and cook for 2 minutes until slightly nutty.
- Gradually whisk in the warm milk, a cup at a time, ensuring no lumps form. Bring to a simmer, whisking constantly, until the sauce coats the back of a spoon. Remove from heat and stir in nutmeg, salt, and white pepper.
- Phase 3: Assembly. Preheat oven to 375°F (190°C). Grease a 9x13 inch baking dish.
- Spread a thin layer of ragù on the bottom of the dish. Top with a layer of lasagna noodles. Spread 1/3 of the remaining ragù over the pasta. Dollop 1/3 of the ricotta cheese, drizzle with béchamel (about 1/4 total), and sprinkle with Mozzarella and Parmesan.
- Repeat the layering process two more times: Pasta, Ragù, Ricotta, Béchamel, Cheese.
- Finish the top layer with pasta, cover entirely with the remaining béchamel, and top generously with the remaining Mozzarella and Parmesan cheese.
- Cover the dish tightly with foil and bake for 30 minutes. Remove foil and bake for another 15-20 minutes, until the top is golden brown and bubbling.
- Let the lasagna rest for 15-20 minutes before slicing. Garnish with fresh parsley, if desired, and serve.