To make the chickpeas, heat the olive oil in a large Dutch oven over medium heat. When the oil is hot, add the pancetta and cook until the fat has rendered and the pancetta is crispy on the edges, about 3 to 4 minutes. Add the garlic and crushed red pepper flakes or chiles, and cook, stirring, until the garlic is golden on the edges, about 2 minutes. Add the drained chickpeas and enough cold water to cover the chickpeas by about 2 inches. Then add the bay leaves and rosemary sprigs, and bring to a simmer. Partially cover the pot and cook until the chickpeas are tender, about 1 hour. Discard the bay leaves.

To make the lagane, put the flour in the work bowl of a food processor and pulse several times to aerate. In a spouted measuring cup, combine the eggs, olive oil, and 1/3 cup cold water. Beat with a fork to combine.

With the processor running, pour the egg mixture through the feed tube and process until the dough forms a ball around the blade. If the dough doesn’t begin to form a ball after about 15 seconds, add a little more flour (if it is too wet) or water (if it is too crumbly) and process until you get a ball. Once the ball forms, process about 30 seconds to get a smooth and homogeneous dough.

Dump the dough onto the counter, and knead a few times to make a completely smooth ball of dough that springs back when pressed. Wrap the dough in plastic, and let rest at room temperature for 30 minutes. (The dough can also be made a day ahead, wrapped, and refrigerated. Return to room temperature before proceeding.)

To roll the pasta, cut the ball of dough into 6 pieces. Keep the pieces covered as you work, and line several baking sheets with floured kitchen towels.

Flatten each piece, then roll it through the widest setting of a pasta machine several times, folding like a letter (rectangle) each time to smooth and strengthen the dough. Once you have a smooth rectangle, continue to roll the pieces through each setting, stopping at the next-to-last setting. Lay the pieces, without touching, on the floured towels.

Cut the pieces into thirds. Roll lengthwise and cut into strands about 3/4-to-1-inch thick (slightly thicker than pappardelle). Dust the strands of pasta with flour and form into loose nests on the floured baking sheets.

Bring a large pot of salted water to boil for pasta. Transfer the chickpeas and enough cooking liquid just to cover them to a large skillet and bring to a simmer. Add the pasta to the boiling water and cook until al dente, just about 2 minutes after the water returns to a boil. Transfer the pasta to the sauce with a spider and tongs. Drizzle with olive oil and add the parsley. Toss to coat the pasta with the sauce, adding a little more chickpea cooking liquid if it seems dry. Remove the skillet from the heat, add the grated cheese, toss, and serve.