I make my frittatas in a 10 inch cast iron pan. For this size of pan, I use 5 large eggs and it feeds 2-3 people, depending on what else you might be serving with it. If you have a larger pan, just add another egg or two and extra vegetables.
Regarding the vegetables, you can use pretty much anything you have on hand. The only proviso is that root vegetables should be pre-cooked (I steam them beforehand) and other harder vegetables such as broccoli should be lightly steamed or blanched first. The quantities of vegetables are fairly flexible. Using lots of vegetables will give a fatter frittata, whereas using less vegetables will give a thinner, flatter frittata, but still tasty!
I usually add cheese to my frittatas, which is tasty but not 100% necessary. I use either grated cheddar or crumbled feta.
Garden Vegetable Frittata
1 tablespoon oil (butter/lard)
1 small onion, finely diced
6-8 leaves kale, rinsed and coarsely chopped
1 1/2 cups loosely packed grated courgette
4-5 button mushrooms, sliced
Sea salt and pepper
Grated cheese or crumbled feta (optional)
Chopped parsley (optional)
1. Heat oil in an ovenproof pan such as cast iron. Add onions and saute for 5 minutes or so.
2. Add vegetables and saute until they are just tender (don’t overcook the vegetables).
3. While vegetables are cooking, crack eggs into a small bowl. Add salt and pepper and whisk together. I add enough salt so that the egg mixture tastes a little too salty, because when the egg is mixed with the vegetables the saltiness becomes diluted.
4. Make sure the vegetables are spread out evenly in the pan, then pour the egg mixture over the vegetables, making sure no patch is missed.
5. Sprinkle over the cheese, if using.
6. Turn the heat to low and cover the pan. Cook until it has started to set around the edges, which takes about 5-7 minutes. Meanwhile, turn on the broiler.
7. Place the pan underneath the broiler and cook for another 3-5 minutes or so, until the top of the frittata is set and turning light golden brown.
8. Remove from the oven and let the frittata rest for a couple minutes before cutting into it.
I like to serve this with pan-fried potatoes and a side salad.