01 - Pat chicken thighs dry with paper towels. Season both sides generously with salt, black pepper, smoked paprika, and dried thyme.
02 - Heat olive oil and unsalted butter in a large skillet or Dutch oven over medium-high heat. Sear chicken thighs, skin-side down, for about 6 minutes per side until deeply golden and crispy. Remove chicken and set aside.
03 - Add sliced onions to the same pan. Sauté, stirring occasionally, until onions are soft and golden, about 8 minutes. Stir in minced garlic and cook for 1 minute until fragrant.
04 - Sprinkle flour evenly over the onions. Stir and cook for 1 to 2 minutes, ensuring the raw flour taste is cooked out.
05 - Gradually pour in chicken broth while whisking constantly to prevent lumps. Bring the mixture to a gentle simmer.
06 - Nestle the seared chicken thighs back into the skillet, skin-side up. Spoon some of the onion gravy over each piece.
07 - Cover and simmer on low heat for 25 to 30 minutes, or until chicken is fully cooked and gravy has thickened.
08 - Taste the gravy and adjust seasonings if needed. Serve chicken thighs garnished with the rich onion gravy and fresh parsley, if desired.