Fluffy frittata with spinach

Ingredients: 8 eggs, separated,2 cloves garlic, finely chopped,½ tsp ground pepper, freshly ground,3/4 teaspoon nutmeg,1 ½ Tbs olive oil,1/3 cup parmesan,½ cup ricotta cheese,1/4 teaspoon salt,140 g fresh spinach, cleaned, blanched, well-drained and chopped,140g frozen chopped spinach, thawed and wrung dry or
Instructions:

1. In a medium oven-proof skillet heat the olive oil, add the garlic and cook until softened.In a glass or metal bowl, beat the egg whites until stiff peaks form. In another bowl, beat the egg yolks and stir in the spinach and ricotta cheese; season with the salt, pepper and nutmeg. Fold in the egg whites.
2. Pour the mixture into the hot skillet and cook over medium heat until just set around the edges, about 2 minutes.
3. Transfer the frittata to the oven and bake at 200C until golden and fluffy, about 15 minutes.
4. Sprinkle the parmesan all over the top and bake for 2 minutes.
5. Cut into wedges and serve immediately.

Source