In a large, heavy-bottomed pot, add olive oil, and begin to saute the pancetta or bacon over medium-high heat. When sufficiently browned, remove all but 2 tsp or so of the fat.
Add onions and celery, sweat three minutes or so until they soften, add garlic, cook 1 minute or until fragrant. Add pimento (or roasted red peppers), cook for a minute or so, then stir in hot pepper flakes (or cayenne), and anchovy paste, if you’re using it.
Add tomatoes, paste, and chicken broth, stirring until tomato paste is smooth. Add sugar, bay leaf and basil. Make sure it comes to a simmer if it already isn’t, then turn heat down to medium-low, cover and let simmer for at least 40 minutes or so, stirring fairly frequently.
Add pasta, and a little extra water if needed (I went with a bit under 1.5 cups of additional water), stir, and simmer, till pasta is tender. You will need to stir pretty frequently, or else surrender yourself to bottom-stick-stew.