Add the chopped onion, celery, carrots and pancetta to the pot. Stir, then cover with a lid and cook the soffritto for about 10 minutes, checking and stirring every 2 minutes to prevent burning.
After around 7 minutes, when the vegetables are soft and glossy, pour in a splash of wine and mix it. Close the lid again and let the flavors combine for another couple of minutes.
Drizzle in a little more oil, then add the ground beef. Use a wooden spoon to break up the meat thoroughly and mix it well with the soffritto.
Once the meat begins to brown and turns grey, pour in the remaining wine and stir well. Season generously with salt and pepper, and let it simmer for 10 minutes.
Next, pour in the passata.
Cover with a lid and cook the ragu on low heat for 3 hours. Stir every 30 minutes, scraping the bottom to make sure nothing sticks.
After 3 hours, remove the lid and continue cooking uncovered for another hour to reduce and intensify the flavor. Stir regularly and adjust the seasoning with more salt and pepper if needed.
Optional but recommended: For a silkier, more balanced sauce, add a splash of full cream milk and cook for another 5 minutes before turning off the heat.
Making the Bechamel Sauce
Place a small pan over medium-low heat and add the butter. Once melted, remove it from the heat and stir in the flour until smooth and well combined.
Return the pan to the stove and begin adding the milk a little at a time, stirring continuously.
As the sauce thickens, continue adding milk in small amounts, whisking gently until you reach a smooth, creamy consistency.
Turn off the heat, then add a pinch of nutmeg. Mix well.
Assembling the Lasagna
Start by spreading a thin layer of bolognese sauce on the bottom of your baking dish. Then lay down the first pasta sheet, trying not to have any gaps.
Spoon over a scoop of Bolognese sauce and spread it evenly from edge to edge, making it mostly even but not too generous!
Add a few spoonfuls of béchamel and sprinkle 2 tablespoons of grated Parmigiano Reggiano and other cheese on top.
Repeat the layering process: pasta, ragù, béchamel, and cheese, pressing each layer down gently as you move through to help the lasagna settle.
For the final layer, place one last pasta sheet on top. Spread the remaining béchamel sauce generously across the surface to help seal the lasagna and than cover with a LOT of shredded Emek cheese for the crust.