i buy the big field or portobello mushrooms and freeze them. I cook them in the oven from frozen and, apart from the stalk, they are fine.
They are also fine if you stuff them first:
remove the stalk, mix ceam cheese, herbs, breadcrumbs, garlic, pine nuts (or whatever you like!); then put two tgether, stuffing to stuffing and freeze. They will seperate easily and cook from frozen in about 30 mins!
You can freeze mushrooms.I think they sell frozen sliced mushrooms in Iceland.
However ..
1. Choose young, firm, medium mushrooms with tightly closed caps. 2. Wash well, trim off ends, and sort by size. Slice larger mushrooms, if desired. 3. Blanch small mushrooms 3 minutes; large mushrooms 4 minutes. Add 1 tablespoon lemon juice to each quart of blanching water. Cool; drain well. Or cook mushrooms in a frying pan with a small amount of butter until almost done. Cool. 4. Pack in containers. Seal, label, and freeze. 5. Cook frozen mushrooms just until heated through.
From ashtray recipes.
I freeze mushrooms for cooking. The button mushrooms I freeze whole and use in things like chicken and mushroom casserole or pie. The larger ones I slice and use in bolognese or add to pasta sauces or pilafs or rissottos.