Add wilted spinach and other ingredients into food processor, mix together until well blended, (try the mixture at this point to determine whether you would like to add more flavour/any other ingredient).
Remove mixture with a spoon and put into a cleaned mushroom cap. Continue until no more mixture and mushroom caps.
Put mushrooms onto a baking sheet that is drizzled with a little extra virgin olive oil.
Bake in oven for about 6-8 minutes, until mushrooms have softened.