Frittata with spinach

Ingredients:

• 4 large eggs
• 0.5 cups whole milk
• 0.5 tsp salt
• 1/4 tsp freshly ground black pepper
• 1 cup grated Swiss cheese
• 1 cup grape tomatoes, halved lengthwise
• 2 tablespoons salted butter
• 1 small onion, finely chopped
• 4 cups fresh baby spinach

Preparation:

1. Preheat oven to grill mode.
2. In a medium bowl, whisk together the eggs, milk, salt, and black pepper until smooth. Add the cheese and tomatoes and set aside.
3. In a 9-inch nonstick skillet, melt the butter over medium heat. Add the onion and sauté until soft, about 5 minutes. Add the spinach and cook until wilted, about 2 minutes. Pour the egg mixture over the spinach and cook, without stirring, until the omelet is almost set, 2-4 minutes.
4. Transfer the pan to the oven and broil the frittata until golden brown on top, 5-7 minutes. Remove from the oven and transfer the frittata to a serving platter.