INGREDIENTS
1 tbsp
extra virgin olive oil
8 oz
pancetta (thick cut), diced
1
small white onion, finely diced
3
large garlic cloves, finely minced
2
tablespooons tomato paste
2 tsp
dried red pepper flakes*
1 28 ounce can
of crushed San Marzano tomatoes
3/4 oz
parmigiano-reggiano cheese, finely grated (plus more for serving)
salt
freshly ground black pepper
1 lb
dried spaghetti pasta
1 tbsp
unsalted butter