Preheat oven to 400 °F (200 °C).
In a small bowl, mix rosemary, garlic, chopped pimento pepper, lemon zest and juice, olive oil, salt, and pepper.
Brush the marinade all over the chicken and inside the cavity; stuff with extra rosemary and lemon pieces. Tie legs and tuck wings.
Place chicken breast-side up on the middle rack; roast uncovered. Baste every 15 minutes with accumulated juices.
Roast for about 1 hour, or until the internal temperature reaches 165 °F (74 °C) in the thickest part.
Let the chicken rest for 10 minutes before carving to retain juices.