Deep-Frying stuffed mushrooms?
If you try to fry them, you'd do well to coat them with breadcrumbs (using egg as an adhesive). Depending on the size of the mushrooms you may even need to do 2-3 layers.

If you don't coat them, they'll probably loose too much water and taste weird. I have deep fried coated muchrooms before (delicious!) at 170°C, however I never tried it with stuffed mushrooms. Personally I disliked them deep fried without coating, but I guess to each their own.