Here is one that Cathy shared. I haven't tried it yet, but it sounds good and close to what you are wanting.

Creamy Mushroom Sauce For Steak-Mustangs
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2 tablespoons butter

½ onion, minced

1 clove garlic, finely minced

2-3 cups sliced fresh mushrooms

¾ teaspoon kosher or sea salt

Ground black pepper

1/8 teaspoon ground nutmeg (optional)

3 tablespoons whiskey

1 tablespoon balsamic

½ cup heavy cream

1 tablespoon finely minced fresh herb of your choice (chives, parsley, tarragon, basil)
. Heat butter in sauce pan over medium heat. When butter starts bubbling,
add onions and sauté until onions are just, translucent, and just
slightly golden; about 3 minutes. add garlic and sauté for an
additional minute until the garlic is fragrant.

Turn heat to high and add mushrooms all at once. Immediately start
tossing so the onion garlic butter mixture is evenly distributed among
the mushrooms. Sauté mushrooms until they are browned and softened,
about 3- minutes. Season with salt, pepper, and nutmeg.

Pour in whiskey and balsamic and let mixture bubble a bit to burn off
some of the alcohol. Turn heat down just a bit and add in heavy cream.
Let bubble for another 30 seconds and then taste to adjust the salt.
Stir in the freshly minced herbs and pout over just grilled steak

Thanks!!!