Grate the zest from 1 lemon. Squeeze 1/3 cup juice from the lemons.
Heat the oil in a 6-quart saucepot over medium-high heat. Add the chicken in batches and cook for 10 minutes or until well browned on both sides. Remove the chicken from the saucepot. Pour off all but 1 tablespoon pan drippings.
Reduce the heat to medium. Add the garlic and rosemary to the saucepot and cook and stir for 30 seconds. Stir in the tomatoes and broth.
Increase the heat to medium-high. Return the chicken to the saucepot and heat to a boil. Reduce the heat to medium-low. Cover and cook for 30 minutes or until the chicken is cooked through. Remove the chicken to a serving platter, cover and keep warm.
Increase the heat to medium-high. Heat the broth mixture to a boil and cook for 10 minutes or until the mixture is reduced by half. Remove the saucepot from the heat. Stir in the lemon juice. Pour the mixture over the chicken. Sprinkle with the lemon zest.