Dredge chicken breasts in seasoned flour. Melt 2 tbsp butter in skillet over med-hi heat and saute chicken breasts until browned, turning once 3-4 min. total and remove. Add 1 tbsp of butter to skillet and melt, add red peppers and mushrooms and saute until softened.
In medium saucepan combine remaineding butter and cream over medium heat until butter melts gradually stir in parmesan.
Slice chicken into stips. Top cooked fettucine with chicken and vegetables and pour cream sauce over. Season with black pepper and serve.