Season chicken breasts on both sides with salt, pepper, paprika, garlic powder, and onion powder.
Heat olive oil in a large skillet over medium-high heat.
Add chicken breasts and sear for about 5-6 minutes per side, until golden brown and cooked through. Remove chicken and set aside.
In the same skillet, melt butter over medium heat.
Sprinkle in the flour, stirring constantly to make a roux, cooking for 1-2 minutes.
Slowly whisk in chicken broth until smooth, scraping up any browned bits from the skillet.
Add heavy cream, dried thyme, and mustard powder. Stir well and let the gravy simmer until thickened, about 3-4 minutes.
Return the chicken breasts to the skillet, spooning gravy over them.
Simmer for another 2-3 minutes to heat through.
Garnish with chopped parsley and serve hot with mashed potatoes, rice, or steamed veggies.