Heat olive oil in heavy 2 qt saucepan until shimmering. Add sliced garlic and saute until oil is infused with garlic flavor. Then remove the garlic. Add diced bacon, celery, and diced onion stems to the hot oil and stir around allowing the vegetables to soften and the bacon to brown. This takes from 3 to 5 minutes.
Add diced tomatoes, if using them, and continue stirring until the tomatoes break down and soften somewhat.
Add the warm water, beans, salt, pepper and cook for 5 minutes on medium high heat. Add ditalini pasta, (and cut up frankfurters, if using), and bring the soup to a boil; then turn down to low or low-medium and cook for 8 minutes. Check occasionally and stir, making sure the liquid doesn't evaporate. Turn off the heat and taste the soup. If the flavor seems weak, you can add a knorr chicken bouillion to the hot soup and stir it in until it dissolves, or you can add chicken broth.
This soup reheats well and also freezes well.
Recipe serves 4 - 6.