Instructions:
- Phase 1 (Ragu): Heat oil/butter in a Dutch oven. Sauté onion, carrot, and celery (soffritto) until softened (about 10 minutes).
- Add ground beef and sausage to the soffritto. Break up the meat and cook until deeply browned. Drain off any excess fat.
- Deglaze: Pour in the red wine. Bring to a simmer and scrape up any browned bits from the bottom. Reduce volume by half.
- Simmer: Stir in crushed tomatoes, beef stock, bay leaf, and oregano. Bring to a gentle bubble, then reduce heat to low. Cover partially and simmer for 2–3 hours, stirring occasionally, until rich and thick. Remove bay leaf and season with salt and pepper.
- Phase 2 (Pasta/Béchamel): Combine 300g flour, eggs, 1 tsp olive oil, and salt for the pasta. Knead until smooth (8-10 minutes), wrap, and rest for 30 minutes.
- Roll the pasta dough thinly into sheets (setting 6 or 7 on a machine) roughly the size of your baking dish. Briefly blanch sheets in boiling salted water (about 30 seconds per side) and shock in ice water. Lay flat on kitchen towels to dry slightly.
- Make Béchamel (Roux): Melt 75g butter in a saucepan. Whisk in 75g flour to form a smooth paste (roux). Cook for 2 minutes.
- Gradually whisk in the warm milk until no lumps form. Bring to a gentle boil, whisking constantly, until the sauce coats the back of a spoon thickly. Remove from heat; stir in nutmeg, salt, and white pepper.
- Phase 3 (Assembly): Preheat oven to 375°F (190°C). Lightly grease a 9x13 inch baking dish.
- Layer 1 (Base): Spread a thin layer of ragu, followed by a thin layer of béchamel, across the bottom of the dish.
- Add a layer of blanched pasta sheets, followed by a generous layer of ragu, a layer of béchamel, and a sprinkle of Parmesan.
- Repeat layering (Pasta, Ragu, Béchamel, Parmesan) until the fillings are used, usually resulting in 4-5 pasta layers.
- Top Layer: Finish with a final layer of pasta, covered generously with the remaining béchamel, and finally top with the mozzarella and remaining Parmesan.
- Bake: Cover the dish loosely with foil and bake for 30 minutes. Remove foil and bake for another 15 minutes until the cheese is golden brown and bubbling.
- Rest: Let the lasagna rest on the counter for 15 minutes before slicing to allow the layers to set.