Pat the chicken thighs dry with paper towels—this is crucial for achieving crispy skin, so don't skip this step. In a small bowl, combine salt, black pepper, and smoked paprika. Rub the olive oil all over the chicken pieces, then generously season each thigh with the spice mixture, making sure to coat both sides and under the skin where possible.

Preheat your oven to 400°F. Arrange the seasoned chicken thighs skin-side up in a large roasting pan (approximately 9x13 inches or similar), spacing them out so they're not crowded. Scatter the whole peeled garlic cloves and fresh rosemary sprigs around the chicken. Roast uncovered for 30 minutes at 400°F until the skin begins to brown and crisp.

After 30 minutes, reduce the oven temperature to 375°F and continue roasting uncovered for another 20 minutes. The chicken should be mostly cooked through at this point, and the skin will have developed a deeper golden-brown color. I like to give the pan a gentle shake halfway through this phase so the garlic cloves toast evenly on all sides.

Cover the pan loosely with foil and roast for a final 10-15 minutes (total cooking time approximately 60-65 minutes) until the chicken reaches an internal temperature of 165°F when measured at the thickest part of the thigh. The foil prevents the skin from burning while allowing the meat to finish cooking through gently. Transfer to a serving platter with the roasted garlic and crispy rosemary sprigs.