Season chicken with salt, pepper, paprika, and garlic powder. Lightly dredge in flour.
Heat olive oil in a large skillet over medium heat. Sear chicken 4–5 minutes per side until golden brown. Transfer to a plate.
In the same skillet, melt butter. Add onions and cook 5–7 minutes until soft and golden. Stir in garlic and cook 1 minute.
Sprinkle in 2 tablespoons flour and stir constantly for 1 minute to make a roux.
Gradually whisk in chicken broth. Bring to a simmer and cook 2–3 minutes until slightly thickened.
Stir in heavy cream if using. Return chicken to the skillet, nestling it into the gravy.
Cover and simmer on low for 10–15 minutes, until chicken is cooked through and smothered in rich gravy.
Garnish with parsley and serve hot.