Preheat broiler. In a medium bowl whisk together eggs, salt, and crushed red pepper. Heat olive oil in a 10-inch oven-going skillet over medium-high heat. Layer zucchini slices on bottom of skillet in an even layer. Cook for 3 minutes, turning once. Top with cherry tomatoes. Pour egg mixture over vegetables in skillet. Top with mozzarella balls and walnuts. Cook over medium heat for 4 to 5 minutes or until sides begin to set, lifting with a spatula to allow the uncooked portion to run underneath.