Heat beans and stock in a small saucepan. Just cover beans with stock. Don't let it get mushy.
Brown pancetta in large pan
Add onion and red pepper and cook till onions are soft
Add garlic. Cook for a few minutes
Add a splash of white wine if you want and reduce.
Add the tomato sauce and stock. Cook for 15 minutes
Cook pasta just before al dente and put in the sauce
Turn heat to low and let cook until pasta is done
Add pasta water if needed
Top with fresh parsley and grated cheese. Parmesan or pecorino.