Heat oven to 375°. In saucepan, combine water and bouillon. Bring to a boil. Add rice. Remove from heat. Cover and let stand 5 minutes, until liquid is absorbed. Stir in spinach and bell pepper; mix well. Flatten each chicken breast to about 1/4 inch, pounding between 2 pieces of waxed paper. Season with salt and pepper, if desired. Place 1/4 of rice mixture on each chicken breast. Roll up by tucking in edges. Divide crescent roll dough into 4-inch squares. Press each square to measure about 6 x 6 inches. Place chicken in center of dough and fold to enclose chicken. Press edges to seal. Place on greased baking pan, seam side down. Bake 25 to 30 minutes, or until golden brown.