- 1 tablespoon oil, plus additional for pan
- 1/2 bunch beet greens
- 2 tablespoons minced shallots
- 2 cloves garlic, minced
- Pinch of red pepper flakes
- 3 tablespoons red wine vinegar
- Salt and pepper, to taste
- 1 cup egg whites
- 1/2 cup whole milk
- 1/4 cup shredded Gruyere cheese
Preheat oven to 375° F. Generously spray 6 muffin cups with oil.
Remove stems from leaves; finely chop stems and leaves and keep separated.
Heat oil in a sauté pan over medium heat. Add stems, shallots and garlic and cook until stems are just tender, 5 to 7 minutes. Stir in leaves, red pepper flakes and vinegar. Cover and cook until leaves are tender, stirring occasionally, about 5 minutes. Season with salt and pepper. Let cool and squeeze out extra moisture, if necessary. Divide mixture among prepared muffin cups.
Whisk together egg whites, milk and cheese; season with salt and pepper. Divide between each muffin cup.
Bake until eggs are set and lightly golden, about 25 minutes. Let cool 10 minutes before serving or refrigerate and serve chilled.