Chicken Breasts with Spaghetti

• 4 boneless chicken breasts, pounded to 1/2 inch thickness*
• 1 large egg
• 1/2 cup milk
• seasoned bread crumbs
• 2 to 3 tablespoons olive oil
• 8 slices mozzarella cheese, or more
• 1 jar (16 to 24 ounces) spaghetti sauce
• fresh shredded or grated Parmesan cheese
• 8 ounces spaghetti or linguine