In a large skillet over medium heat, cook chicken in 1 tablespoon butter until a thermometer reads 165°, 4-5 minutes on each side. Remove and keep warm.
Add wine to pan; cook over medium-low heat, stirring to loosen browned bits from pan. Add cream and bring to a boil. Reduce heat; cook and stir until slightly thickened. Stir in rosemary and remaining 3 tablespoons butter until blended. Serve sauce with chicken.