You can pretty much throw anything into a frittata. Any cheese. Any (pre-cooked) vegetables or meat: peppers, cauliflower, sliced sausage, chopped crispy bacon, strips of cooked chicken breast. It's a great empty-out-the-fridge one-pot meal. It can be beautiful to look at. It can also be funky and very green and super messy to look at. In my opinion, it must have one or all of these toppings: sriracha, ketchup, chopped chives, avocado slices, and sour cream.
This recipe calls for potatoes and asparagus. But you can just as easily add finely chopped kale (or any combo of greens like chard, arugula, spinach) into the onions instead of the asparagus. Or add it along with the asparagus, though that would be a bit heavy on the greens (I love this, my kids do not).
It's best eaten right away. There's something so exciting about the crispy bubbling feta-topped egg cake. But you can also serve it room temperature. Or heat it up the next day.
for the vegetables:
2 tablespoons olive oil
2 tablespoon butter
1/2 yellow onion, peeled and diced
2 large leeks, cleaned, trimmed of tough green part, thinly sliced
big pinch salt
10 small potatoes cooked in salty water until tender and then halved (purple or yukon gold work well)
8 spears asparagus, trimmed, quickly cooked in salty water but still crisp, sliced into 1 inch pieces
1 clove garlic, grated, chopped, or pressed
2 teaspoons lemon zest.
for the eggs:
3/4 cup creme fraiche or heavy cream
3/4 grated firm or semi-firm cheese (any combination of parmesan, percorio, manchego, gruyere, cheddar)
big pinch salt
for when it goes under the broiler:
1/2 cup feta cheese (or goat), crumbled
1/4 cup parmesan, grated
for the toppings:
chopped parsley and chives
sour cream, creme fraiche, or yoghurt (another nice option is sour cream thinned with heavy cream)
Crank a 10 inch oven-safe pan (I use cast iron) to medium heat. Add olive oil and butter. When butter is melted, add onions, leeks, salt, and pepper. Cook, stirring often, until tender and starting to brown a bit (about 20 minutes).
While onions are cooking, vigorously whisk together eggs, creme fraiche, cheese, salt, and pepper until well-combined and foamy. Set aside.
Preheat oven to a high broil.
Turn heat up to high under onions and toss in potatoes and asparagus. Add grated garlic and lemon zest. Cook, stirring entire time, for a minute.
DASH AND BELLA
Give the eggs one final whisk and then pour over the vegetables. Stir until all vegetables are coated with eggs. Turn down to medium heat. Then leave it alone to start to set. You can put a lid on it. Or not. Be aware of heat going onto bottom of pan and make sure it's not too hot. The eggs don't taste so good when they get too brown.
Once the eggs are about halfway set, take off heat and sprinkle top with feta, parmesan, and some crunchy salt. Place under the broiler and don't walk away. If if browns too quickly, place on a lower shelf in the oven. Check for doneness after a minute by poking around in the middle of the frittata with a paring knife. An undercooked frittata is nasty. Try to find that perfect moment when the very center isn't quite set because it will continue to cook a bit after you take it out of the oven.
While it's still piping hot, slide a knife around and dislodge the sides from the pan. Use a spatula and slowly slide it under the frittata. Do this all the way around, making sure you make it all the way to the center. You can serve it in the cast iron pan. Or you can flip it out on a plate. Just make sure you serve it crispy-feta side up.
Serve with toppings (see ingredients above for ideas).