- 1 Tbsp. butter
- 1 Tbsp. olive oil
- 12 eggs
- 1 russet potato, diced
- ½ cup of whole milk
- 20 fresh basil leaves, divided
- 1 tsp. salt
- ½ tsp. pepper
- 20 Cherry tomatoes, halved
- 8 ounces fresh mozzarella cheese, sliced in rounds
- 1 cup gruyere cheese, shredded
- Preheat the oven to 400 degrees.
- Place a 10.25 inch cast iron skillet over medium-low heat for 4 to 5 minutes.
- While pan is heating, set aside half basil leaves and finely chop remaining half.
- Add the butter and the olive oil.
- Add the potatoes in and stir until tender, about 5 minutes.
- In a large mixing bowl, whisk together eggs, milk, salt, pepper, and chopped basil until well blended.
- Pour half of the egg mixture into the skillet and cook 3 to 4 minutes, until bottom has begun to set.
- Carefully place half of the cherry tomatoes and the Gruyere into the eggs.
- Pour in the rest of the egg mixture, and place remaining tomatoes on top.
- Cook another 4 to 5 minutes on the stovetop. Transfer to oven.
- Bake until the top is set and sides begin to pull away from the skillet, about 8 to 10 minutes.
- Remove skillet from oven, carefully place mozzarella slices on top, and let cool for 5 minutes as cheese melts.
- Use a spatula to remove frittata from skillet. Garnish with remaining basil and serve immediately.