4 piece(s) chicken, breast, bone-in, about 2 1/2 pounds, trimmed and skin removed
Preheat oven to 400°F. Line a baking sheet with foil and lightly oil or coat it with cooking spray.
Season chicken on both sides with 1/8 teaspoon salt and 1/4 teaspoon pepper, then rub with 1 1/2 teaspoons thyme. Place bone-side up in a single layer on the prepared baking sheet. Roast for 15 minutes.
Meanwhile, heat jelly, vinegar and the remaining 1/2 teaspoon thyme in a small saucepan over medium-low heat until the jelly is melted. Season with the remaining 1/8 teaspoon salt and pepper and remove from the heat.
Turn the chicken meat-side up. Brush liberally with the jelly glaze. Continue to roast, brushing twice with the remaining glaze, until the chicken is cooked through, about 15 minutes more.