Season with salt and pepper.
Mix lemon juice, rosemary, garlic, paprika, and 2 tablespoons olive oil. Pour over chicken breasts and lemon halves.
Let marinate for at least 30 minutes, ideally overnight.
Preheat oven to 400 degrees.
Heat grill pan over high heat and oil lightly. Add chicken breasts, skin side down, and lemon halves, flesh side down. Cook until dark grill marks are achieved.
Flip chicken and grill on opposite side until charred.
Transfer to oven until cooked to 165 degrees, about 15-20 minutes.
Serve chicken with grilled lemons for squeezing.