1. Preheat your oven to 375°F (190°C). This temperature is perfect for rendering the fat under the skin and roasting the chicken to a golden crisp without drying it out.
2. Pat the chicken thighs dry with paper towels — this little step is crucial for crispy skin. Season both sides generously with salt, pepper, and smoked paprika.
3. Heat the vegetable oil in a large oven-safe skillet or Dutch oven over medium-high heat. When the oil shimmers, add the chicken thighs skin-side down. Let them cook undisturbed for 5-7 minutes until the skin is deeply browned and crisp. Flip and sear the other side for 3 minutes.
4. Remove the chicken to a plate and reduce the heat to medium. Add the sliced onions and cook gently until softened and lightly caramelised, about 8-10 minutes. Stir in the minced garlic and cook for another minute until fragrant.
5. Pour in the chicken broth, apple cider vinegar, brown sugar, and Dijon mustard. Stir well to combine, scraping the bottom of the pan to lift any browned bits — this is where the magic happens.
6. Return the chicken thighs to the pan, skin-side up. Sprinkle dried thyme and red pepper flakes if using. Spoon a little of the sauce over the chicken, but keep most of the skin exposed so it stays crisp.
7. Transfer the skillet to your preheated oven. Roast uncovered for 25-30 minutes or until the chicken reaches an internal temperature of 165°F (74°C) and the sauce has thickened slightly.
8. Remove from the oven and let the chicken rest for 5 minutes. Garnish with freshly chopped parsley before serving.

One of my favourite memories is the quiet anticipation as the house filled with the aroma of these thighs roasting, the kind of smell that pulls everyone into the kitchen, hungry and happy. I often serve this with a crusty loaf of bread to soak up every last drop of that tangy sauce.