I made this recently for a work function. I call it a picnic frittata as you can eat it cold, or if you like, you can heat it up. This is gluten free and suitable for vegetarians, but not vegans.
2 tsp oil;
4 large mushrooms, chopped;
4 spring onions, finely sliced;
2 cloves garlic, finely sliced;
6 sprigs thyme, leaves picked;
2 cups shredded cheese (of your choice, but I used a tasty cheese);
1/2 cup milk.
Preheat a fan forced oven to 180 celcius. Lightly spray a 30 X 20cm baking dish with oil.
Heat the oil in a heavy based saucepan. Add the ingredients for mushroom mix. The idea of the salt is to make the excess liquid come out of the mushrooms, if you leave it in, it will make your mixture too runny. Cook for 5 – 10 minutes, stirring often, until the mushrooms have condensed and you can see a bit of liquid in the bottom of the pot. Strain – discard liquid. Allow to cool in the strainer for a while.
While the mushroom mix is cooling, crack the eggs into the baking dish, add the cheese and milk and beat until the egg yolks are well combined. Add the mushroom mix and stir the mixture until everything is evenly combined.
Put in oven and bake 20-30 minutes – monitor it to make sure it doesn’t burn. It is done when lightly browned & a knife inserted leaves a cut in the mixture.
Allow to cool a little, then cover with cling film and refrigerate overnight. Once cool, it is easier to cut cleanly. You can cut while warm, but you might get a little bit of crumbling. Cut into preferred sizes. I cut mine into bite sized pieces, but you could cut into larger pieces if preferred.
If you wanted to make a version with ham, you could cut a couple of slices of ham into small pieces and mix in to the egg mix with the mushroom mix.