01 - Pat chicken thighs dry with paper towels. Generously season both sides with salt, black pepper, smoked paprika, and dried thyme.
02 - In a large skillet or Dutch oven, heat olive oil and unsalted butter over medium-high heat until the butter is melted and begins to foam.
03 - Place chicken thighs skin-side down in the hot pan. Sear until the skin is golden brown and crisp, about 6 minutes per side. Remove thighs and set aside on a plate.
04 - Add the sliced yellow onions to the skillet. Cook, stirring occasionally, until the onions are softened and golden, about 8 minutes. Add minced garlic and sauté for 1 minute until fragrant.
05 - Sprinkle all-purpose flour (or gluten-free flour) over the onions. Stir well to coat and cook for 1–2 minutes, removing the raw flour flavor.
06 - Gradually pour chicken broth into the skillet, whisking constantly to dissolve any lumps. Bring the mixture to a gentle simmer until a smooth gravy forms.
07 - Return seared chicken thighs to the skillet, skin-side up. Spoon some of the gravy and onions over the chicken.
08 - Cover the pan with a lid and reduce heat to low. Simmer for 25–30 minutes, until the chicken is cooked through and the gravy has thickened.
09 - Taste the gravy and chicken. Adjust salt and black pepper as needed.
10 - Serve chicken thighs smothered with the rich onion gravy. Garnish with chopped fresh parsley if desired.