Bring water to a boil in large Dutch oven. Add 1 tablespoon salt and potatoes. Cook 3 minutes. Drain well.
Meanwhile, in large bowl, beat eggs, milk, flour, 1 teaspoon salt and pepper. Add onion, ham, parsley, 1/2 cups Cheddar cheese, Parmesan cheese, and drained potatoes; mix well. Spoon mixture into Slow Cooker ceramic pot sprayed with non-stick cooking spray. Sprinkle with remaining 1/2 cup Cheddar cheese. Cover and cook at LOW 2 1/2 to 3 hours, or until center is set and knife inserted in center comes out clean. Cut into squares to serve.
TIP: To determine if center is set without removing lid, tap lid to remove condensation. Gently shake Slow Cooker ceramic pot to see if center jiggles or is firm.
8 to 10 servings
Recipe Courtesy of KitchenAid