Prep the oven and baking sheet. Preheat the oven to 350°F degrees. Place a rack over a baking sheet.
Make the spice rub. In a small bowl, whisk together the paprika, garlic powder, onion powder, Italian seasoning and chili powder.
Prep the chicken. Pat the chicken thighs dry with paper towels. Generously season the chicken thighs with about ¾ of the seasoning rub. Place the seasoned chicken on the prepared baking sheet.
Prep the dredge. Season the flour with remaining seasoning rub, salt and pepper. Transfer 2 tablespoons of the seasoned flour to a smaller bowl.
Dredge the chicken thighs. Dredge the chicken thighs through the flour mixture making sure they are fully coated. Shake off any excess flour. Place the thighs back on the rack and repeat with remaining chicken thighs.
Pan sear the chicken. Heat the olive oil in a large oven safe skillet over medium-high heat. Add the chicken thighs to the skillet and cook for about 5 minutes per side until browned. The chicken won't be fully cooked at this point. Transfer the chicken back to the rack.
Cook the onion and garlic. In the same skillet add the butter, onion and cook for 3 to 5 minutes until softened and translucent. Add the garlic and cook for another 30 seconds until aromatic. Stir in the red pepper flakes.
Sprinkle flour. Sprinkle the reserved seasoned flour over the onions and continue cooking while stirring for another 2 minutes to remove the raw flour taste.
Make the gravy. Start pouring chicken broth while continuously whisking and cook for a couple more minutes until the gravy comes to a simmer. Whisk in the heavy cream and bring to a simmer. Taste for seasoning and adjust with salt and pepper as needed.
Add chicken and braise in the oven. Add the chicken back to the skillet and spoon some of the gravy over the chicken. Cover the skillet and transfer it to the oven. Cook in the oven for one hour.
Garnish and serve. Garnish with fresh parsley and serve over mashed potatoes or rice.