4 bacon slices, coarsely chopped
4 skinless boneless chicken breast halves
3 tablespoons chopped fresh Italian parsley, divided
8 ounces large crimini (baby bella) mushrooms, halved
1 medium yellow or red onion, cut into slivers
2 garlic cloves, minced
1 1/2 cups dry red wine
1 1/2 cups low-salt chicken broth, divided
4 teaspoons all purpose flour
Preheat oven to 300°F. Sauté bacon in large nonstick skillet over medium-high heat until crisp. Using a slotted spoon, transfer to bowl. Sprinkle chicken with salt, pepper, and 1 tablespoon parsley. Add to drippings in skillet. Sauté until cooked through, about 6 minutes per side; transfer to pie dish (reserve skillet). Place in oven to keep warm.
Add mushrooms and onions to skillet; sprinkle lightly with salt and pepper. Sauté until mushrooms are brown, about 4 minutes. Add garlic; toss 10 seconds. Add wine, 1 1/4 cups broth, bacon, and 1 tablespoon parsley. Bring to boil, stirring occasionally. Boil 10 minutes.
Add 1/4 cup broth to flour, stirring until smooth. Add flour mixture to sauce. Cook until sauce thickens, 3 to 4 minutes. Season sauce to taste with salt and pepper. Arrange chicken on platter; stir juices from pie dish into sauce and spoon over chicken. Garnish with parsley.