Combine basil, olive oil, pine nuts, garlic, pecorino cheese, and Grana Padano to make pesto.
Melt butter in a saucepan.
Add flour and cook for 1-2 minutes.
Gradually whisk in milk until smooth.
Bring to a simmer and cook until thickened.
Season béchamel with nutmeg, salt, and pepper.
Layer lasagna sheets, pesto, and béchamel sauce in a baking dish.
Top with extra cheese.
Bake until golden brown and bubbly.
