Sweat the aromatics: Warm 1 tablespoon olive oil and a small knob of butter in a large pot.
Add pancetta (if using), onion, carrot, and celery. Cook over medium-low heat until soft and fragrant, about 8–10 minutes. Add garlic for the last minute.
Brown the meat: Increase heat to medium-high.
Add ground beef and pork with a big pinch of salt and pepper. Cook, breaking up the meat, until lightly browned. Don’t rush—color builds flavor.
Build the ragù: Stir in tomato paste and cook for 1 minute to caramelize.
Pour in red wine and let it reduce by half. Add crushed tomatoes and a splash of milk if using. Reduce to a low simmer, partially cover, and cook 45–60 minutes, stirring occasionally.
Adjust salt and pepper.
Make the béchamel: In a saucepan, melt 3 tablespoons butter. Whisk in flour and cook 1–2 minutes until foamy but not browned. Slowly whisk in 3 cups milk, a little at a time, until smooth.
Simmer gently until thick enough to coat a spoon, 5–7 minutes. Season with salt, pepper, and a pinch of nutmeg.
Prepare the pasta: If using fresh sheets, blanch in salted boiling water for 30–45 seconds, then cool briefly on a towel. If using no-boil sheets, you can use them as is, but ensure your sauces aren’t too thick so they hydrate in the oven.
Preheat and set up: Heat oven to 375°F (190°C).
Grease a 9x13-inch (23x33 cm) baking dish. Keep ragù and béchamel warm so they spread easily.
Layer the lasagna: Spoon a thin layer of béchamel in the dish. Add a layer of pasta.
Spread a modest layer of ragù, then béchamel, then dust with Parmesan. Add a light sprinkle of mozzarella if using. Repeat 3–4 times, finishing with pasta, béchamel, and a generous shower of Parmesan.
Avoid overfilling; aim for about 5–6 total pasta layers.
Bake: Cover loosely with foil (tent it so it doesn’t stick to the top). Bake 25 minutes. Remove foil and bake 15–20 minutes more, until bubbling and lightly golden on top.
Rest and serve: Let the lasagna rest at least 15–20 minutes before slicing.
This helps the layers set and gives you clean, neat squares.