Layers of fresh pasta, homemade Bolognese, béchamel sauce, and Parmigiano-Reggiano - all baked to perfection.
Bolognese Sauce: heat a Dutch oven or heavy stainless steel pot over medium-high heat. Add the olive oil and heat up. Add the onions, carrots, and celery and cook for 7-10 minutes, stirring occasionally. The vegetables will become soft and translucent.
Add the ground beef to the vegetables and allow it to brown, ensuring to break the beef up into smaller pieces while cooking.
When beef has cooked, add the tomato paste, salt, black pepper, oregano, and paprika. Stir and cook for about 2 minutes, until the tomato paste has deepened in colour and aroma.
Add the beef broth, stirring and scraping any stuck-on bits at the bottom of the pot. Add the passata or crushed tomatoes, thyme sprigs, and brown sugar and stir. Once it starts bubbling, add the milk and stir well to combine.
Allow the mixture to come back up to a boil, reduce to low, cover the pot, and simmer for 1-2 hours. The longer the better! Remember to give it a stir every 30 minutes.
Once finished simmering for 1-2 hours, taste and adjust for salt. If you find the sauce too sour, add 1 tsp more of brown sugar and recheck. Once you've adjusted the Bolognese to your liking, remove from heat and set aside until ready to use.
Béchamel sauce: heat a saucepan over medium heat. Add the unsalted butter and allow to melt. Add the all-purpose flour and whisk together for 1-2 minutes, until the flour no longer has a raw flour smell to it.
Gradually add the warmed/room temperature milk to the butter/flour mixture. Start with roughly 1 cup of milk and whisk thoroughly into the butter/flour. Add another cup and whisk to combine. Then, gradually add the remaining milk, whisking continuously. You should end up with a lump-free mixture.
Continue to whisk to prevent the milk from burning at the bottom. The mixture will slowly begin to thicken. Once it slightly thickens, add the salt, white pepper, and grated nutmeg. Continue to whisk until it thickens up a bit more and can coat the back of a wooden spoon. Taste and add more salt, to taste (if needed). Remove from heat and set aside. Note: béchamel sauce thickens more as it cools.
Assemble the lasagna: preheat the oven to 375F and get a 9x13 baking dish with high sides ready to go.
Spread a ladleful of Bolognese sauce evenly on the bottom of the baking dish. Next, cover the bottom with lasagna sheets, ensuring the bottom is completely covered. Next, pour a little more than 1/3 of the Bolognese sauce over the lasagna sheet layer - spread evenly. Next, pour a little more than 1/3 of the béchamel sauce over the Bolognese layer - spread evenly. Next, sprinkle a little more than 1/3 of the grated cheese over the béchamel layer.
Repeat the steps: cover this layer with lasagna sheets. Evenly spread a little more than 1/3 of the Bolognese sauce over. Evenly spread a little more than 1/3 of the béchamel sauce over. Sprinkle a little more than 1/3 of the grated cheese over.
Finish the layers: add the last layer of lasagna sheets. Spread the remaining Bolognese sauce over the lasagna sheets. Spread the remaining béchamel sauce over. Sprinkle the remaining grated Parmigiano-Reggiano over top.
Cover the baking dish with foil, place in the preheated oven on the middle rack, and bake for 40 minutes. Remove foil and bake for an additional 20 minutes.
Remove from oven and allow the lasagna to stand for 20 minutes before cutting into it. Finish with a sprinkle of your favourite herb (parsley, chives, etc. this is optional) and enjoy.