01 - Pound the chicken breasts to an even 1/2-inch thickness for uniform cooking.
02 - Combine flour, salt, and pepper in a shallow bowl. Dredge each chicken breast in the flour mixture, shaking off any excess.
03 - Heat olive oil in a large skillet over medium-high heat. Add chicken and cook for 4–5 minutes per side until golden and cooked through. Transfer to a plate and loosely cover with foil.
04 - In the same skillet, add mushrooms and cook for 4–5 minutes until browned and tender. Add garlic and sauté for 1 minute until fragrant.
05 - Pour in chicken broth, grape juice, balsamic vinegar, and thyme. Bring to a simmer, scraping up any browned bits from the pan.
06 - Stir in the cornstarch slurry and simmer for 2–3 minutes until the sauce thickens.
07 - Return the chicken to the skillet and simmer for 2–3 minutes, spooning sauce over the top.
08 - Garnish with chopped parsley and serve immediately.