In a large pot, cook bacon over medium heat until almost crisp. Stir often.
In the meantime, add onions, celery and bell peppers to a microwave-safe bowl. Cook in the microwave for 3 minutes, to soften.
Add the softened vegetables and garlic to the pan of cooked bacon. Continue to cook for 3 minutes, stir often.
Whisk in flour; cook for 2 minutes.
Stir in broth, tomatoes, vinegar or lemon juice, Worcestershire, Tabasco sauce, thyme, sugar, and bay leaf. Bring to a boil, then turn heat down to low and simmer for 10 minutes to thicken. Stir often.
Add in chicken and cook for 3 minutes. Add the spinach and mix well. Cook for 1 more minute.