1 1/2 pounds chicken thighs, skin-on, bone-in, trimmed of excess fat
1 tablespoon whole grain mustard
1 tablespoon lemon zest (1 teaspoon for rub and 2 teaspoons for sauce)
1 1/2 teaspoons dried oregano
1/2 teaspoon dried thyme
1/4 teaspoon kosher salt
2 tablespoons olive oil (1 tablespoon for rub, 1 tablespoon for cooking)
1/4 cup (60 ml) lemon juice (about 1 lemon)
1 1/4 cups (300 ml) low-sodium chicken stock
2 garlic cloves, smashed
1 tablespoon unsalted butter
1 tablespoon all-purpose flour

Heat oven to 400 degrees F (200 C). Make rub for chicken. Combine mustard, 1 teaspoon of the lemon zest, oregano, thyme, salt and 1 tablespoon of the olive oil in a small bowl. Use fingers or a brush to coat chicken on both sides with the mustard rub. In another bowl or measuring jug, combine remaining lemon zest (2 teaspoons), lemon juice and the chicken stock. Set aside. Heat remaining tablespoon of oil in a large oven-safe skillet or frying pan over medium heat. Add the smashed garlic then cook about 1 minute or until you can smell toasted garlic and the garlic has browned around the edges. Remove and discard the garlic, but leave the oil. Add chicken, skin-side down into the hot garlic-infused oil and cook 2 to 3 minutes or until the skin has turned golden brown. Flip the chicken then add the lemon juice mixture from before. Stir then slide the pan into the oven and bake 25 to 35 minutes or until a thermometer inserted into the thickest part of the chicken reads 175 degrees F (79 degrees C). Remove pan from oven then transfer the chicken to a plate and cover with aluminum foil. There should still be liquid in the pan. Place the pan over medium heat and bring the liquid to a gentle simmer. In a small bowl, use your fingers to mix butter and flour together, making a dry, crumbly paste. Whisk the flour and butter into the sauce. The sauce will thicken slightly and look glossy. Nestle the chicken back into the pan then serve.