For the pasta and filling
1 teaspoon kosher salt, plus more for the pasta pot
1 pound paccheri
3 cups fresh whole-milk ricotta, drained overnight
3 cups freshly grated Grana Padano, or Parmigiano-Reggiano
2 tablespoons chopped fresh Italian parsley
For the spring vegetable sauce
3 tablespoons extra virgin olive oil
1 cup chopped trimmed scallions, tender green and white parts
½ cup chopped onion
2½ pounds fresh peas in the pod, shelled
1¼ teaspoon peperoncino (crushed red pepper)
Salt to taste
3 cups marinara sauce
1 cup finely diced zucchini
In a large, heavy casserole, heat the olive oil over medium heat. Add the scallions and onions and cook until wilted, about 4 minutes. Add the peas, fava beans, zucchini and peperoncino, season lightly with salt. Stir well and add the marinara. Simmer altogether for 10- 15 minutes, stirring occasionally.
Meanwhile, fill the pasta pot with salted water, and heat to a rolling boil. Drop in the paccheri, stir well, and return the water to a boil. Cook the paccheri until flexible, but still quite al dente. Test doneness by plucking one out of the water and pressing it gently. It must be soft enough that you can squeeze it without snapping the tube, yet firm enough to stay open, without collapsing, while you fill it.
When cooked enough, quickly lift out all the paccheri with a spider or strainer, and drain them well in a colander.
Heat the oven to 400 degrees and brush the baking dish with olive oil. For the stuffing, dump the drained ricotta into the bowl , 1 cup of the grated grana, and whisk the eggs in, then stir in the parsley, until all smooth.
Spread a cup of the vegetable sauce in the bottom of the baking dish. With a soup spoon, fill the paccheri one at a time with the ricotta stuffing. Lay them in the baking dish, on top of the vegetable sauce close together, in neat rows, filling the pan with one layer of stuffed pasta tubes—if you have more, arrange them in a second layer on top. Spoon and spread the remaining sauce over the paccheri, and sprinkle the remaining grated cheese on top.
Tent the baking dish with a sheet of aluminum foil, arching it above the pasta and pressing it loosely against the sides. Set the dish in the oven, and bake for 45 minutes, then remove the foil, and bake another 15 minutes or so, until the cheese is nicely browned and crusty and the sauce is bubbling.
Lift out as many paccheri as a wide spatula will comfortably hold being careful to keep the topping in place, and with the help of another smaller spatula or knife slide each portion onto a warm dinner plate.