The preparation time is a bit long, but these are yummy and can be varied with the ingredients you have at hand.
I always make "too much" of the veg mixture, since I love combining the hot cooked taste with the uncooked crispy mixture.
Carefully break off the stems of the mushrooms - don't worry about leaving a bit behind.
Use a melon-ball iron or a teaspoon to gouge out the brown parts, the rest of the stem and a bit of the floor of the mushroom.
(I haven't tried this yet, but you could dry-fry the mushrooms for a few minutes until some of the liquid comes out, so there isn't so much liquid in the end product).
Take what you gouged out of the mushrooms, add some of the mushroom-end of the stems (not the bottom ends, they are dry and icky).
Peel the outer skin off the stalks of cauliflower and broccoli. (Use the "flowers" in your main course or another day). Grate the carrots to make them easier to finely chop, or use them just grated.
Add finely sliced raw vegetables as you like and then finely chop everything.
Put the chopped veg in a bowl and add sea salt, crushed or finely chopped garlic and some creme fraiche or sour creme (or even cream). Keep adding "liquid" until the mixture becomes well coated, but not so much that it is dripping with liquid (there will be more liquid in the mushroom when it is cooked, as the liquids from the mushroom will seep into the mixture).
Use a teaspoon or fork to insert the mixture up to the edge (or slightly over) of the mushroom.
Put the sliced or grated cheese over the top so it covers the mixture and the top edge of the mushroom well.
DO NOT WORRY IF THERE IS "TOO MUCH" VEG SALSA! I always make way too much, so I am sure I have enough for the dish, and so I have a healthy veg salsa I can enjoy with this dish and as a leftover.
Bake at about 180-200 C for about 20 minutes until the cheese is nicely golden, but not burned.
Serve piping hot from the oven (2 per person is a nice apperetif) and serve the rest of the veg salsa as a garnish side dish.