Cook bacon pieces (4) in a large soup pot over medium, stirring often until the bacon is cooked. Transfer cooked bacon to a paper towel-lined plate. Remove and discard all but 2 generous tablespoonfuls of the drippings in the pot.
Add onion (1 cup) and garlic (2 cloves) and saute over medium heat until it begins to soften about 5 minutes. Sprinkle flour (2 tablespoons) over vegetables and cook, stirring constantly, for 1 minute.
Remove pot from the heat and slowly whisk in chicken broth (6 cups) until smooth. Return to heat and stir in Better Than Bouillon (1 heaping tablespoon), Italian seasoning (2 teaspoons), thyme (1 teaspoon), salt (1 teaspoon), pepper (1/2 teaspoon), bay leaf (1), petite diced tomatoes (1 (14.5-ounce) can), tomato sauce (1 (8-ounce) can), potatoes (2), and frozen vegetables (1 (16-ounce) package).
Bring to a boil then immediately reduce heat and simmer, uncovered, until the potatoes are tender when pierced with a fork, about 25 minutes. Adjust seasoning. Add more chicken broth if the soup gets too thick. Stir in chicken (4 cups) and cooked bacon and heat through. Adjust to taste as needed Garnish with fresh herbs of choice (2 tablespoons) and serve.
Notes
Cook the flour for a full minute. That quick cook-off removes any raw flour taste and gives the broth a smoother, more “finished” texture.
Whisk the broth in slowly off the heat. This prevents lumps and keeps the roux silky instead of clumpy.
Cut the potatoes small and evenly. Small cubes cook faster, stay tender, and help naturally thicken the soup as they simmer.
Add the chicken at the end. Since it’s already cooked, stirring it in during the last few minutes keeps it juicy instead of dry.
Expect it to thicken — and plan to loosen it. If the soup gets too thick (especially after chilling), add a splash of broth or water when reheating.
Finish with fresh herbs if you can. A sprinkle of parsley, thyme, or chives right before serving makes the whole pot taste brighter and fresher.