Heat some olive oil in a frying pan over medium high heat and add the mushrooms.
Cook the mushrooms for the side you're going to add the stuffing for about 2 minutes or until golden brown.
Flip them and cook for about 2 minutes more. You can add some sea salt and black pepper to taste, I didn't do it, but it's up to you.
Mix the rest of the ingredients in a bowl or a jar and stuff each one with a generous amount of filling using a spoon. Cook for 2 minutes more and they're ready to eat.