Marinade chicken breasts in caesar dressing for at least 3 hours, up to overnight.
Cook bacon until crisp, remove from pan and drain off all but about 2 tbsp of the fat. Heat pan to medium-high heat.
Remove chicken from marinade and cook in bacon fat until well browned. You don't have to cook the chicken through, just get some color on it. Remove chicken from pan and place in casserole dish.
Drain off all the bacon fat from the pan and add 3 tbsp of butter. Once melted stir in the onion and mushrooms. Cook until soft and starting to caramelize- 5-7 minutes.
Stir 3 tbsp of flour into the onions and mushrooms and cook for 1 minute.
Stir broth and cream into the flour mixture, bring to boil -constantly stirring- for 2 minutes. Remove from heat.
Stir in salt, pepper, lemon juice, cheese, and parsley and pour over the chicken in the casserole dish. Top with fresh tomatoes and bake, uncovered for 20-25 minutes or until the sauce is bubbly and chicken is cooked through.
While the chicken is baking, cook 1 lb angel hair pasta on the stove-top and drain.
Remove chicken from the oven, stir pasta into the sauce and serve topped with crumbled bacon and more fresh parsley.