Heat a Dutch oven or saucepot with EVOO over medium-high heat.
Add the pancetta and render for 2 minutes; add the pork and lightly brown and crumble. Add the fennel, onion, carrot, garlic, chili pepper, herbs, salt and pepper; partially cover and cook for 10 minutes, stirring occasionally. Stir in the tomato paste, cook for 1 minute, then add the wine and reduce for 2 minutes. Add the stock and cover; simmer for 30 minutes. Add the tomatoes and simmer, partially covered, for 20-30 minutes more at a low bubble, stirring occasionally.
Bring a pot of water to a boil for the pasta. Salt the water and cook the pasta to al dente, removing 1/2 cup of the starchy cooking water just before draining. Drain the pasta and add back to the warm pot, but not over heat. Toss the pasta with butter to melt, then add the starchy cooking water and half of the sauce; toss with some cheese.
Serve in shallow bowls topped with more meat sauce and cheese.