Chicken and orzo skillet dinner

Chicken second courses

1 pound skinless, boneless chicken breast halves, cut into bite-sized pieces 8 cups water 12 ounces uncooked orzo 2 cups chopped tomato (about 2 medium) 2 teaspoons no-salt-added tomato paste ½ teaspoon salt ½ teaspoon crushed red pepper ¼ teaspoon black pepper 3 cups baby spinach leaves 3 ounces feta cheese, crumbled (about ¾ cup)