First, position a rack in the center of your oven and preheat it to 400°F (200°C). Take the chicken thighs out of their packaging and use paper towels to pat them completely dry. This step is crucial—removing excess moisture is the key to achieving perfectly crispy, golden-brown skin. Once dry, season both sides of the chicken generously with salt and freshly ground black pepper.
In a large, 9-to-12-inch oven-safe skillet (cast iron works wonderfully here), heat 1 tablespoon of butter and the olive oil over medium-high heat. The oil helps prevent the butter from burning while still giving you that rich flavor. When the pan is hot and the butter/oil mixture is shimmering, carefully place the chicken thighs in the skillet, skin-side down. Let them sear without moving them for 2-3 minutes, until the skin is deeply golden and crispy. Flip the thighs and sear for another 2-3 minutes on the other side. The chicken will not be cooked through at this point; you are just building flavor and texture. Transfer the seared chicken to a plate and set it aside.
Add the diced onion and cubed potatoes to the same skillet, which now contains all the flavorful chicken drippings. Sauté the mixture for 5-7 minutes, stirring occasionally, until the potatoes start to turn lightly golden-brown at the edges and the onions have softened and become translucent. Season with a pinch of salt and pepper to taste, then transfer the potato and onion mixture to a bowl and set aside.
Reduce the skillet’s heat to medium and melt the remaining tablespoon of butter. Add the minced garlic and sauté for about 30-60 seconds until it becomes fragrant. Be very careful not to let it burn, as burnt garlic will turn bitter and ruin the sauce. Pour in the honey, soy sauce, and white vinegar, stirring to combine everything. Bring the sauce to a gentle simmer and let it cook for 4-5 minutes, stirring occasionally. The sauce is ready when it has thickened slightly and can coat the back of a spoon.
Return the seared chicken thighs to the skillet, making sure to place them skin-side up to keep the skin crispy. Nestle the cooked potatoes and onions in the spaces around the chicken. Using a spoon, generously drizzle some of the honey garlic sauce over the chicken and potatoes to ensure every piece is coated in flavor. Carefully transfer the skillet to the preheated oven and bake for 25-30 minutes. The dish is done when the chicken is cooked through, reaching an internal temperature of 165°F (74°C) on a meat thermometer, and the potatoes are tender enough to be easily pierced with a fork.
Once out of the oven, let the dish rest for about 5 minutes. This allows the juices in the chicken to redistribute, resulting in a more tender bite. Just before serving, sprinkle the minced fresh parsley over the top for a burst of color and fresh flavor. This dish is best served warm, directly from the skillet.