A cock-up on the supply front means we’ve got an excess of chestnut mushrooms. We actuallyhave an overall excess of veg but this is the urgnet issue. With the next few days meals planned, I can’t easily swap a dish without then risking other ingredients going off.
So, my friends, your challenge this evening (or whatever time it is in your part of the world), is to come up with sormething that will include mushrooms in significant quantity - that I can then freeze.
Make mushroom duxelle for compactness then use later in soups, pasta sauce, etc.
Mock liver pate
On the rare occasions when I do my own grocery shopping, if there are mushrooms marked down for quick sale, I snap them up, slice, drizzle with soy sauce or teriyaki, and either saute on high heat or bake on a sheet pan at 400F. The idea is to get them dry, with brown edges. Then freeze them for later use. BTW, Jacques Pepin is a fan of ordinary button mushrooms; if the gills have opened they are considered old, but have more flavor than most gourmet shrooms.
I use a pound in chicken, wild rice and mushroom soup, a favorite. I start with a recipe like this and change it up each time.
What a fabulous problem to have @Harters! My best suggestions would be to sauté and freeze like others have suggested. Sometimes I also add onions, and then garlic at the end so they’re ready to go in a variety of things.
OR, I would make the base for mushroom soup. The 2 recipes I like are the old Moosewood Cookbook recipe for Hungarian Mushroom Soup, or Anthony Bourdain’s famous mushroom soup. Just don’t add the dairy, until it’s thawed, warmed, etc or whatever the recipe says. Both easily found on the internet. Haven’t tasted chestnut shrooms, unless they go by a different name in the US.
Even if you don’t freeze it, once they’re cooked, the duxelles will keep in the fridge for at least several days. I recently found myself in a similar position (but with just a little less than a pound of them) and I don’t bother to go as far as making “proper” duxelles (I stopped before they were as dry as they might’ve been). I just chopped them coarsely and then sauteed them with a couple of shallots, then refrigerated them in a covered container. Ended up mostly using them in scrambled eggs and ersatz-omelettes over the following 5-6 days, and they remained fine until they were gone…
LIke mini-portobellos - about the size of normal white button mushrooms
https://www.sainsburys.co.uk/gol-ui/product/mushrooms/sainsburys-closed-cup-chestnut-mushrooms-300g
Thought maybe they were. You probably know they’re called cremini or baby Bella’s over here. When dried, porcini. They’re my favorite all-purpose mushroom.
They’re usually called “cremini” mushrooms here, or (usually only when they’re packaged, with printed labels) sometimes names like “Baby Bellas”…
We cross posted, and our replies are almost identical! I think you were actually reading my mind with powers I have yet to learn. 
this freezes beautifully.
mushroom ragu
1 cup dried porcini mushrooms
2 tablespoons olive oil
2 tablespoons butter
1 medium carrot, finely chopped
1/2 medium onion, finely chopped
1 celery stalk, finely chopped
3 garlic cloves, minced
1/2 teaspoons red pepper flakes
1 pound mixed mushrooms
mix of crimini, shiitake, oyster, sliced or coarsely chopped
1/2 cup marsala, madeira or dry sherry wine
1/4 cup tomato paste
1 tablespoon sherry vinegar
salt and pepper, to taste
pasta or polenta
freshly chopped parsley, for serving
shaved parmesan cheese, for topping
Pour 1 1/2 cups near-boiling water over porcini mushrooms and let steep for 20 to 30 minute or until softened. Strain, reserving liquid, and finely chop mushrooms. Set aside.
In a large stock pot or dutch oven set over medium-high heat, heat olive oil and butter until melted and sputtering. Add onion, carrot and celery and cook for 5 minutes until starting to soften. Season with a generous pinch of salt and pepper. Add garlic and red pepper flakes and sauté for 3 to 5 minutes until fragrant.
Add mushrooms and cook, stirring occasionally, until mushrooms have cooked down to less than half their original volume and turned a rich golden brown, about 15 to 20 minutes.
Add wine, tomato paste, and 1 cup of reserved mushroom steeping liquid and cook until liquid is saucy and velvety in texture, about 10 minutes more. Feel free to add additional mushroom liquid or pasta water as desired to achieve a looser consistency.
Stir in sherry vinegar, and season to taste with salt and pepper.
Serve over pasta (or other base of your choice) and top with chopped parsley and shaved parmesan, as desired.
Buy time. Clean, slice, dehydrate (oven works fine - you don’t need anything fancy), store in airtight container. Shelf stable for a year or so I believe. See https://www.trail.recipes/dehydrating123/dehydrating123-how-to-dehydrate-mushrooms/ .
I had to check but actually a different, if similar, mushroom. You might be interested in this “naming” article on the website of one of the supermarket chains we often shop at.
Love this.
Or just a simple saute that can adapt for various future usage: sliced mushrooms cooked with olive oil or butter with chopped shallot or garlic with a splash of vinegar or white wine. Try to freeze in small portions for easy versatile use.
Another vote for dehydrating. I recently had too many mushrooms piling up, sliced and dried and ready for soups or whatever when there’s no mushrooms in the house. Gone are the days I dash to the grocery store for a ‘crucial’ ingredient. Lessons in adaptability😉
If you believe Wiki they are all variations of the same mushroom:
Agaricus bisporus
When immature and white, this mushroom may be known as common mushroom, white mushroom,[3] button mushroom,[3] cultivated mushroom, table mushroom, and champignon mushroom. When immature and brown, it may be known variously as Swiss brown mushroom, Roman brown mushroom, Italian brown mushroom, cremini/crimini mushroom,[4][5] chestnut mushroom, and baby bella.[4]
I’ve never dried shrooms myself, but buy them in large containers that usually contain a silicone packet to absorb excess moisture. The shrooms last indefinitely.
If you really have a LOT, I’d do half as mushroom pate or faux-duxelles (not that dissimilar), and dry-sauté half in chunks or slices for incorporation into your planned menu over the next week.
The pate/duxelles can be frozen, but likely won’t need to be as it’s so flexible - fabulous as an appetizer or snack, in quiche or other eggs, turned into a quick cream of mushroom soup, or sauce for chicken or steak, or pasta sauce, and so on.
Many thanks for all the advice. In the event, I went down the slice, fry and freeze route. Open froze, so they’re now loose in a bag, ready to go.
