Spinich-Chicken Breast Rolls

* 4 med. boneless, skinless chicken breast halves (about 1 1/4 lb. total)
* 1 egg white
* 1/2 of a 10 oz. pkg. frozen chopped spinach, thawed & well drained
* 1/3 c. low-fat cottage cheese, drained
* 4 oz. part-skim mozzarella cheese, shredded (1 c.)
* 1 1/4 c. spaghetti sauce (about 1/2 of a 26 oz. jar)
* 2 Tbl. tomato paste
* 6 oz. pasta, cooked & drained (gluten-free if desired)

Preheat oven to 375. Place each chicken breast between plastic wrap; lightly pound with flat side of meat mallet to about 1/4" thickness. In bowl, stir together: egg, spinach, cottage cheese & 1/2 mozzarella. Spoon onto chicken, leaving 1/2" border. Roll up from narrow side. Place seam sides down, in 2-qt. rect. baking dish. Combine spaghetti sauce & tomato paste; spoon over chicken. Bake, covered, for 25 minutes. Uncover; sprinkle with remaining mozzarella. Bake, uncovered, about 25 minutes more, or until chicken is no longer pink & cheese is light brown. Let stand 10 minutes. If desired, serve on top of pasta.