Make-Ahead Frittata Squares with Spinach, Tomatoes, and Feta Recipe

Preheat the oven to 350 degrees F. Butter a 2-quart baking dish.

In a large skillet over medium heat, heat the olive oil. Add the tomatoes and cook, stirring often, for 2 minutes, or until just starting to soften but not yet falling apart. Transfer to a separate dish and set aside.

Add the the scallions to the pan and cook for about 1 minute, or until softened. Stir in the spinach and salt. Cook, stirring often, until the spinach wilts.

Remove the pan from the heat and cool for a few minutes. Stir in the crumbled feta cheese.

In a large bowl, gradually whisk the milk into the sour cream until smooth. Whisk in the eggs, salt and pepper.

Transfer the spinach filling from the pan into the baking dish and pour the egg mixture over top. Scatter the tomatoes on top of the eggs so they peek out, and sprinkle with the parsley.

Bake for 40 to 45 minutes, or until the eggs are set.

Cool the frittata for at least 10 minutes, and cut into 9 servings. Store leftovers in the refrigerator for up to a week, and reheat in the microwave.