Preheat oven to 375. Place flour in shallow dish. Sprinkle chicken with salt; coat with flour. Heat 2 Tbsp. olive oil in large skillet over medium-high heat until hot. Add chicken; cook, turning once until golden(2-4 minutes per side) Remove chicken from skillet & place in 13x9 baking dish.
Heat remaining olive oil in same skillet over medium heat until hot. Add garlic & onion, cook until garlic is fragrant & onion is tender (1-2 minutes) Increase heat to medium high; add whipping cream, Parmesan & pepper. Cook till sauce is bubbly & slightly thickened (2-3 minutes). Spoon sauce over chicken.
Bake chicken until an instant read thermometer inserted in center of chicken reads 180 degrees (8-12 minutes). Sprinkle with parsley.