Season the chicken: Pat chicken dry. Season both sides with salt, pepper, and a light sprinkle of dried thyme. If using flour, lightly coat each piece and shake off excess.

Crisp the bacon: In a large skillet over medium heat, cook chopped bacon until crisp, 6–8 minutes. Transfer bacon to a plate, leaving 1–2 tablespoons bacon fat in the pan.

Brown the chicken: Add a drizzle of olive oil if the pan looks dry. Sear chicken 4–5 minutes per side until golden. It doesn’t need to be cooked through yet. Transfer to a plate.

Sauté aromatics: Add butter to the skillet. Stir in onion and cook 2–3 minutes until softened. Add mushrooms and a pinch of salt. Cook, stirring occasionally, until they release liquid and turn golden, 6–8 minutes. Add garlic and cook 30 seconds until fragrant.

Deglaze and build the sauce: Pour in chicken broth, scraping up browned bits. Stir in cream, Dijon (if using), a pinch of red pepper flakes, and Parmesan. Simmer gently on medium-low until slightly thickened, 3–5 minutes.

Return chicken and bacon: Nestle chicken back into the skillet. Sprinkle in most of the bacon, saving some for garnish. Simmer 5–8 minutes, spooning sauce over chicken, until the chicken is cooked through (internal temp 165°F).

Finish and adjust: If the sauce is too thick, add a splash of broth. If it’s thin, simmer 1–2 minutes more. Taste and season with salt, pepper, and a small squeeze of lemon for brightness.

Serve: Top with reserved bacon and chopped parsley. Serve over mashed potatoes, buttered noodles, rice, or with crusty bread.