I used chard and leeks because it was what I had, but any green or onion could work here. I prefer a thicker frittata slice, so I go with eight eggs in an 8" pan. You could get away with six eggs but note it will be even more veggie packed.
1 leek, halved and cleaned
1 bunch swiss chard, stem and ribs removed (or 5 cups chopped dark leafy green of choice)
2 Tbsp. extra virgin olive oil
1/4 cup heavy cream or creme fraiche
1/2 tsp. cayenne
1/2 cup feta cheese
sea salt + pepper
Preheat the oven to 180C. Warm 1/2 Tbsp. of the oil in a pan over medium heat. Slice the leek into thin half moons and add it to the pan. Sauté for 5 minutes until well softened.
In a large bowl, whisk the eggs and cream well with the cayenne and generous pinch of salt and pepper. Add the leeks into the bowl.
Warm another 1/2 Tbsp. of the oil and sauté the greens with a small pinch of salt until wilted, about 3 minutes. Allow them cool slightly, releasing the steam pockets. Add the greens to the egg bowl along with half the feta and stir everything to mix.
In an 8" pan, preferably non-stick, warm the remaining Tbsp. of olive oil over low heat. Add the egg mixture to the pan, sprinkle the top with the remaining feta and cook for about 5 minutes until the edges start to look cooked. Transfer the pan to the oven and cook for about 15 minutes until you jiggle the pan (with a mitt, it'll be hot) and the center of the frittata is slightly soft. It will set as it cools. Slice the frittata into wedges and serve with warm buttered toast.
Frittata will keep covered in the fridge for a week.
Source : Sprouted Kitchen