Lasagne Roll-Ups
["8 pieces lasagne pasta (8 oz.)", "2 Tbsp. olive oil", "1/4 c. finely chopped onion", "1 3/4 c. stewed tomatoes (14 1/2 oz. can)", "2/3 (6 oz.) can tomato paste", "1 3/4 c. Ricotta cheese (15 oz. container)", "1 1/4 c. frozen, chopped spinach, thawed and well drained (10 oz. pkg.)", "1 c. Mozzarella cheese, divided", "1 egg, slightly beaten", "2 Tbsp. grated Parmesan cheese", "1/2 tsp. salt", "1/4 tsp. pepper"]
["Cook pasta according to package directions; drain and lay flat to cool."]
["pasta", "olive oil", "onion", "tomatoes", "tomato paste", "Ricotta cheese", "frozen", "Mozzarella cheese", "egg", "Parmesan cheese", "salt", "pepper"]