1. Preheat oven to 375°; spray 13 x 9-inch baking dish with cooking spray. In large skillet, melt 1 tablespoon butter over medium heat. Add onion; cook and stir 5 minutes or until tender-crisp. Add garlic and spinach; cook and stir 2 minutes or until fragrant and spinach is wilted. Transfer onion mixture to large bowl. Add latkes and 1 cup cheese; toss and spread in prepared dish.
2. In same large bowl, whisk eggs, 1 cup milk, nutmeg, and 1 teaspoon each salt and pepper. Pour egg mixture over onion mixture; sprinkle with remaining 1 cup cheese and bake 30 minutes or until internal temperature reaches 160°, and top is golden brown and slightly puffed. Cool breakfast bake 5 minutes; cut into 8 (4 1/2 x 3 1/4-inch) pieces.
3. Prepare hollandaise sauce mix with remaining 1/4 cup unsalted butter and 1 cup milk as label directs. Makes about 1 cup sauce.
4. Serve breakfast bake drizzled with sauce

Approximate nutritional values per serving (1 piece breakfast bake, 2 tablespoons sauce): 423 Calories, 30g Fat, 14g Saturated Fat, 355mg Cholesterol, 723mg Sodium, 17g Carbohydrates, 1g Fiber, 5g Sugars, 0g Added Sugars, 21g Protein