Spinach Brunch Bake (vegetarian, low carb, low fat)

• 1/2 cup chopped onion 
• 4 garlic cloves, minced 
• 1 tablespoon butter 
• 8 Eggs or 2 cups egg whites 
• 1 package (10 ounces) frozen chopped spinach, thawed and squeezed dry 
• 1-1/2 cups (6 ounces) shredded part-skim mozzarella cheese 
• 1 cup (4 ounces) crumbled blue cheese, divided 
• 2 plum tomatoes, diced 
• 1/4 cup chopped walnuts 
• 1 plum tomato, sliced, optional

1. Combine onion, garlic and butter in a small microwave-safe bowl. 
2. Cover and microwave 1 minute or until onion is tender. 
3. In a bowl, lightly beat eggs with whisk. 
4. Stir in onion mixture, spinach, mozzarella, 3/4 cup blue cheese, diced tomatoes and walnuts. 
5. Place in a greased shallow 1-qt. baking dish. Bake, uncovered, at 400° for 30-35 minutes or until a knife inserted near the center comes out clean. 
6. Garnish with remaining blue cheese and sliced tomato if desired.