Preheat oven to 375°F. Place flour in a shallow dish or pie plate. Sprinkle chicken with salt; coat with flour. Heat 2 tablespoons of olive oil in a 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 a 13- x 9-inch baking dish.

Heat remaining olive oil in same skillet over medium heat until hot. Add garlic and onion; cook until garlic is fragrant and onion is tender, 1-2 minutes. Increase heat to medium-high; add whipping cream, Parmesan and pepper. Cook until sauce is bubbly and slightly thickened, 2-3 minutes. Spoon sauce over chicken in dish.

Bake chicken until an instant-read thermometer inserted in center of chicken registers 180°F, 8-12 minutes. Sprinkle with parsley.