Bucatini with Pancetta, Tomato, and Onion - Lidia

Ingredients

• Kosher salt
• 5 tablespoons extra-virgin olive oil, or to taste
• 1 medium onion, thinly sliced
• Four ¼-inch-thick slices pancetta or jowl bacon (about 6 ounces), cut into 1½-inch julienne strips
• 2 whole dried red peperoncini (hot red peppers), or ½ teaspoon crushed red pepper flakes
• One 28 oz canned Italian plum tomatoes (preferably San Marzano) crushed by hand plus more if needed
• 1 pound bucatini
• 1 cup freshly grated Pecorino Romano cheese, plus more for passing