1. Sprinkle breast fillets with salt and pepper. Dust with flour, shaking off excess. Heat 1 tablespoon oil in skillet over medium-high heat. Add half the breast fillets and sauté 2 to 3 minutes on each side until golden brown and cooked through. Remove and set aside.
2. Add remaining 1 tablespoon oil, garlic and mushrooms to skillet and sauté until mushrooms are browned. Add chicken broth and capers. Heat broth and simmer on low heat for two minutes. Stir in lemon juice and butter and simmer for 1 minute. Mix cornstarch with water and pour mixture into skillet and stir gently until sauce thickens. Turn off heat.
3. Return cooked breast fillets to skillet, turning to coat with sauce. Serve immediately.