
Clean the mushrooms from any debris or dirt, scoop out the stem and a little bit of the inside into a bowl using a spoon or a small knife, place the heads in a different bowl and season with salt, pepper, balsamic vinegar and oil. Toss the heads around to evenly season and set aside.
Roughly chop the mushrooms stems and pan sear with a slice of butter until golden brown. Remove from heat and add to a bowl.
To the same bowl, add the remaining ingredients such as chopped imitation crab, cheese, pressed garlic, chopped parsley, mayonnaise and season with a pinch of salt and pepper to taste. Mix everything to combine and fill the mushroom caps with the filling.
Place the mushrooms caps on a baking sheet, top with more shredded cheese if desired and bake at 400°F for 10-15 minutes or until the cheese browns and juices start to pool at the base of each mushroom.