1In a small saucepan, warm up the milk over medium heat.
2In a medium skillet, melt the butter over medium heat. Stir in the flour with a wooden spoon, about 5 minutes. Be careful not to burn the flour.
3Add the warm milk to the butter-flour mixture and bring to a boil, whisking constantly. Reduce the heat to medium-low and simmer for about 15 minutes until thickened.
4Season the sauce with freshly grated nutmeg, salt, and pepper to taste. Taste to ensure the flour flavor has dissipated. If you still taste the flour, cook a few minutes longer.
For a thicker besciamella, add 1/2 tablespoon butter and 1/2 tablespoon of flour and cook for a few minutes over medium-low heat, stirring constantly.
To thin a sauce, add 1 tablespoon milk (or 2 if needed).
1Using a mortar and pestle or in a food processor, combine the olive oil, basil, pine nuts, and garlic and blend until a paste forms.
2Add the Parmigiano-Reggiano and Pecorino cheeses, and pulse until smooth.
3Season with salt and pepper to taste(be mindful that that the cheeses are salty).
4 Keep covered, air-tight, in the fridge until you’re ready to use it; this will prevent it from oxidizing and turning dark.
ASSEMBLING THE LASAGNE
1Preheat the oven to 375º F. Now that you have (or have made) the besciamella and the pesto, you only need a cup of freshly grated Parmesan cheese and 1 1/2 (9-ounce) boxes of no-boil lasagna noodles.
2Butter a 9 x 13-inch baking dish or aluminum pan.
3Spread a thin layer of besciamella (about 1/2 cup) over the bottom of the dish. Cover with
a layer of lasagne noodles, then another thin layer of besciamella. Gently spread 4 tablespoons of pesto across the surface, followed by about 2 tablespoons of freshly grated Parmesan.
4Repeat the process until you reach the top, which should be a final layer of noodles and an uppermost layer of besciamella, topped with pesto and Parmesan.
5Bake for about 30 minutes until bubbly and golden brown on top. For a nice crisp coating, turn on the broiler and bake for another 5 minutes(keep a watchful eye on this step, so top does not burn).
6Lest rest for 5 minutes before serving. Keep extra virgin olive oil and Parmesan handy for a final garnish before serving.