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