Finely chop the onions and mushrooms, keep them separate
Melt butter in a large pan
add onions and garlic, cook for 2 minutes
add mushrooms, cook for 8-10 minutes to get moisutre out of mushrooms and reduce them
add salt, pepper, thyme and flour. Cook for 2 minutes stirring constantly to keep flour from burning
Slowly whisk in whipping cream and broth
Simmer for a couple of minutes, mixture will thicken quickly
Use in a recipe right away, or wait for it to cool and freeze
I freeze mine in 2-3 cup portions ready for recipes! Freezes for up to at least 2 months
For my tator tot hot dish, I used 3 cups of this cream of mushroom soup for 2 pounds of ground beef.