Ingredients

• neutral oil (for frying the chicken)
• 4 pounds chicken thighs (trimmed of overhanging fat)
• 2 teaspoons Diamond Crystal kosher salt
• 1 teaspoon black pepper
• 1 cup all-purpose flour (for dredging only)
• 1/4 cup olive oil
• 2 large white onions (sliced root to stem 1/4" thick)
• 12 cloves garlic (halved)
• 1 cup red wine vinegar
• 1 1/2 cups dry white wine
• 1 tablespoon granulated sugar
• 1 1/4 cups low-sodium chicken stock ()
• 3 sprigs rosemary
• 3 large bay leaves
• 3 tablespoons unsalted cold butter (cubed)
• 1/4 cup minced flat-leaf Italian parsley

Instructions

1. Preheat oven to 350f and set the rack to the middle level.
2. Dry off the chicken pieces with paper towels and season with salt and pepper. Dredge the chicken in flour, shake off the excess, and place onto a parchment paper lined baking sheet.
3. Heat a large oven-safe pan to medium heat with a 1/4 inch of neutral oil (vegetable, avocado, etc). Once the oil is shimmering, add the chicken pieces skin side down and sear until golden (about 5 minutes) then flip and cook for another 3 minutes or so. Place the seared chicken onto a plate and repeat with the remaining pieces, working in batches to not overcrowd the pan.
4. Pour out the frying oil and wipe down the pan. Add the olive oil along with the onions and a pinch of salt. Saute the onions until soft (about 7-10 minutes), adding a splash of water along the way if they start to burn. Once they are soft, add the garlic and cook for another 3-5 minutes or until fragrant and golden.
5. Next, add in the white wine, vinegar, and sugar and turn heat to high. With a wooden spoon scrape the bottom of the pan to remove any brown bits. Boil for 5 minutes to reduce the liquid by about half.
6. Add the chicken stock, rosemary, and bay leaves and bring to a boil. Once boiling turn off the heat and add in the chicken pieces, skin side up. Cover the pan tightly with foil and place in the oven. Bake for 20 minutes then remove the foil and continue to cook until the chicken thighs reach at least 185-195f internally after checking with an instant-read thermometer (about 10-15 minutes).
7. Remove the pan from the oven and place the chicken pieces on a platter tented with foil to keep warm. Check the consistency of the sauce. If it is too thin for your liking, place the pan on a burner and bring to a boil for a few minutes to thicken.
8. Once satisfied, turn off the heat and remove the rosemary and bay leaves. Mix in the parsley. Whisk in one cube of butter at a time. Taste test the sauce and season with salt and pepper if required. Pour the sauce over the chicken and serve. Enjoy!