For the béchamel:
- 2 lb heirloom tomatoes, stems removed, quartered
- 1/4 cup (1/2 stick) unsalted butter
- 1/4 cup all-purpose flour
- 1 cup whole milk, heated
- 3/4 tsp salt
- 1/4 tsp freshly grated nutmeg
For the rest of the lasagna:
- 1 tbsp olive oil
- 2 medium white, yellow, or sweet onions, thinly sliced
- 2 large garlic cloves, minced
- 1 tsp salt, divided, plus more to taste
- 2 medium zucchini, sliced into 1/8 inch strips lengthwise
- 1 pint fresh, shucked English peas
- 1 & 1/2 cups ricotta
- 1 tsp lemon zest
- 3 scallions, thinly sliced
- 12 lasagna noodles
- 1/2 lb fresh mozzarella
- 8 to 10 squash blossoms, stamens removed
- 1/2 cup grated pecorino romano, packed
- To make the béchamel, place tomatoes in a blender and purée until smooth. Strain the purée through a fine mesh sieve to remove any skin and seeds. In a medium saucepan, melt butter over medium heat. Add flour, whisk to combine, and cook for 2 to 3 minutes. Add milk 1/2 cup at at a time, whisking well after each addition. Add tomato purée 1/2 cup at a time, again whisking after each addition. Add salt and nutmeg, bring sauce up to a simmer, and cook for 6 to 8 minutes until slightly thickened. If the sauce is grainy due to the tomatoes, use an immersion blender to smooth it out.
- In a large, heavy-bottomed stainless steel pan, add olive oil over medium high heat. When oil is hot, add onions, garlic, and 1/2 tsp salt. Cook for 10 to 12 minutes until translucent and light brown. Transfer to a clean bowl and set aside.
- Bring a medium pot of salted water to a boil. Add peas and cook for 2 to 3 minutes, until vibrantly green and just starting to get tender. Drain and transfer to a bowl of cold water to stop the cooking.
- Preheat oven to 425 degrees F. Place zucchini strips on a parchment paper lined baking sheet. Sprinkle with remaining 1/2 tsp salt. Place in oven and roast for 10 to 15 minutes until the edges are slightly brown and crispy. Remove from oven and set aside. Turn oven down to 350 degrees F.
- Combine ricotta, lemon zest, and scallions in a mixing bowl. Set aside.
- Bring a large pot of salted water to a boil. Add lasagna noodles and cook according to instructions (I par-boiled mine for 4 minutes, then they finished in the oven). Depending on the size of your pot and how quick you are at fishing the noodles out, you might want to boil them in batches so they don’t stick to each other. Remove noodles from the cooking water and place them in one layer on a clean baking sheet.
- To assemble, place a quarter of the béchamel on the bottom of a 3 & 1/2 to 4 quart lasagna pan. Place a third of the noodles on top. Spread half of the ricotta on the noodles, sprinkle half of the onion/garlic mixture, layer half of the zucchini strips, and sprinkle half of the peas on top. Add another quarter of béchamel and another layer of lasagna noodles. Repeat with the rest of the filling, another quarter of béchamel and the final layer of lasagna noodles. Top with the remaining béchamel and mozzarella. Cover with a lightly greased sheet of aluminum foil, place in oven, and bake for 30 minutes at 350 degrees F.
- Remove from oven and turn the temperature up to 425 degrees F. Uncover lasagna, place squash blossoms on top, and sprinkle pecorino all over in one even layer. Return to oven and bake for 15 more minutes. Let cool for 15 minutes before slicing and serving.