1/2 cup chopped onion
4 garlic cloves, minced
1 tablespoon butter
1 10 oz. package frozen chopped spinach, thawed and squeezed dry
1-1/2 cups (6 ounces) shredded mozzarella cheese
1 cup (4 ounces) crumbled blue cheese, divided
2 plum tomatoes, diced
1 plum tomato, sliced, optional
Combine onion, garlic and butter in a small microwave-safe bowl. Cover and microwave about 1 minute (or saute in skillet on stovetop) until onion is tender.
In a bowl, lightly beat eggs with whisk. Stir in onion mixture, spinach, mozzarella, 3/4 cup blue cheese, and diced tomatoes.
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. Garnish with remaining blue cheese and sliced tomato if desired.