Chop mushrooms into 2.5 cm chunks.
Heat 5 ml of olive oil in a pan and toss in mushrooms.
Season and cook on low for 30 minutes until juice evaporates.
Cube two-thirds of the cheese and grate the remaining third.
Whisk eggs in a bowl and season with salt and pepper.
Add three-quarters of the mushrooms and cubed cheese to the eggs.
Keep remaining mushrooms warm in a low oven.
Clean the pan and heat the remaining oil over medium heat.
Pour in egg mixture and scatter grated cheese on top.
Cook on the lowest setting for approximately 20 minutes.
Place under a high grill for 30 seconds to set the top.
Top with reserved mushrooms and serve immediately.