Cook the bacon in a large pan until crispy and set aside on paper towels to drain and cool before crumbling.
Cook the chicken in bacon drippings in the same pan over medium-high heat until lightly golden brown and cooked through, about 3-5 minutes per side, before setting aside.
Add the onions and cook until tender, about 3-5 minutes, before adding the garlic and flour and cooking until fragrant, about a minute.
Add the chicken broth and deglaze the plan by scraping all of the brown bits from the bottom of the pan into the sauce.
Add the balsamic vinegar, maple syrup, mustards, soy sauce, bacon and chicken. Bring the sauce to a simmer and cook until it thickens a bit, about 2-3 minutes.
