7 oz(200g)Parmigiano Reggiano cheese(or Grana Padano), freshly grated
35 oz(1kg)lasagna noodles(Notes: Fresh green spinach noodles are traditional; Lasagna that you boil has superior texture. No-boil/oven-ready lasagna saves time with a loss in quality of texture.)
Measure out ingredients to have everything ready at hand.
Melt the butter in at least a 5 quart pot over medium-low heat.
Sprinkle the butter with flour and cook for 3 to 4 minutes, constantly stirring with a whisk.
Whisk in the milk, about 1/2 cup at a time at first, stirring each time until smooth. Once the paste has transformed into a liquid, you can add the rest of the milk all at once.
Turn heat up slightly and slowly bring to a bubble, stirring rarely at first. Once at a slow bubble, stir often until thickened to a consistency similar to gravy - still pourable - about 5 minutes. Remember, it will continue to thicken as it cools.
Take off heat and immediately stir in nutmeg, salt and pepper.
Prep
Preheat the oven to 350°F (180°C) (If your lasagna is very tall or extra dense, lower to 325°F/165°C)
Prepare Workspace: Lay out the baking pan/s, béchamel, ragù, grated Parmigiano (and any ingredients for variations) for easy reach.
Boil the Pasta (Can skip if using ready-made/no-boil lasagne noodles.)
Put a large stockpot of salted water on to boil. Meanwhile, spread out a silicone baking mat (or use a cooling rack or cutting board) as a landing place for the batches of boiled lasagna noodles.
Boil about 5 to 6 pieces of lasagna at a time, until barely tender. The time will vary depending on the brand of pasta, about 2 to 7 minutes.
Use a large skimmer to transfer the 5 or 6 pieces of boiled lasagna to the silicon mat. Repeat as you build the lasagna.
Assemble
Spread a layer of béchamel on the bottom of the baking pan/s. Cover with a layer of pasta sheets. Don't worry about overlapping a little, and or wrinkled noodles.Cover with thin layer of béchamel (about 1 Tbsp. over each pasta sheet).Cover with a thin layer of ragù (about 2 flat Tbsp. per pasta sheet). Sprinkle grated Parmigiano Reggiano cheese on top.
Repeat until fully assembled.
Top the last layer with a thicker layer of béchamel (paying extra attention to cover the corners so that they don't dry out while cooking), optionally a light layer of meat, if you like, and finally a generous dusting of Parmigiano-Reggiano cheese.
Optional:Add extra spoonfuls of ragú around the edges if there is room, to later be spooned on the individual plates of lasagna (a highly appreciated extra treat).Pour a few tablespoons of broth (or add a few frozen broth cubes) around the sides of the assembled dish for an elegantly relaxed lasagna. This also helps ensure it stays nice and moist while cooking.
Cook & Enjoy
Bake covered with foil for about 30 minutes, then uncover and bake until hot, about another 15 minutes. (If your lasagna is very tall or extra dense, allow extra time.) Test with a knife to make sure hot in the center. Cover to keep warm, and let rest and settle about 5 minutes before serving.
Enjoy in flat pasta bowls or on large plates.
Make Ahead: The béchamel and ragù can be made up to 3 days ahead and stored covered in fridge. Variations:
Fontina or Taleggio – 10oz (280g), sliced or cubed - Distribute over 1 or 2 of the layers.
Dried Porcini– 1 to 2oz (30-60g) - A touch of good quality porcini adds an interesting savory dimension to lasagna. Brush clean, pulverize in a spice mill or food processor and generously sprinkle over the béchamel on 1 or 2 layers.
Storing: Lasagna can be refrigerated, sealed in plastic wrap, for up to 3 days, and in the freezer for up to 3 months.Reheating: To reheat, add broth or dot with butter, cover with aluminum foil, and place in the oven at 350°F (180°C) for 45 minutes, or until hot throughout. If frozen, remove from freezer the night before, and place in the refrigerator to thaw. If cooking directly from the freezer, allow for at least 20-30 extra minutes of cooking time.Portions by Weight (for freezing): About 12 to 14oz (350-400g), per person, is a generous portion size.Yield:16 servings - around 2medium pans of 8 medium portions each, or 8mini pans of 2 generous portions each (either loaf pans, or around 8x5½x1¾" (20cm x 14cm x 4.5cm) rectangular pans).