Mushroom, Onion and Acorn Soup

Any squirrel will tell you, acorns are edible! And, they have a long history as part of the food culture of American Indigenous people who developed ways to remove some the tannins from the nuts, which made them more palatable for us humans. If you can’t find acorn flour, substitute other nut flour or buckwheat flour.

This recipe was inspired by ingredients local to Northern Montana where the television series Yellowstone is set and filmed.

Soup tureen filled with wild morel mushroom and onion, acorn soup and topped with cheese, a dried morel mushroom and toasted baguette slices.
Prep Time: 10 minutes
Cook Time: 40 minutes
Wild Morel Mushroom, Onion and Acorn Soup
Servings: 6
If you can’t find acorn flour, substitute other nut flour or buckwheat flour. Don’t worry about rehydrating dried mushrooms, they will soften up while cooking.


  • ¼ cup butter
  • 3 medium white onions thinly sliced, about 4 cups
  • 2 cloves garlic minced
  • ½ cup red wine
  • 4 cups beef or vegetable stock
  • 2 Tbsp tomato paste
  • 1 Tbsp acorn flour
  • ½ tsp black pepper
  • 1 pound fresh morel mushrooms or 1 ounce dried about 10 mushrooms
  • 1 demi baguette thinly sliced and toasted
  • ¼ cup Parmesan cheese
  • 1 cup shredded Gruyere and/or Swiss cheese


  • Melt the butter in a large Dutch oven or soup pot over medium heat then stir in the onions and garlic to coat. Cook for 15 minutes, or until starting to brown and caramelize. Add the wine then scrape up any brown bits that form on the bottom of the pot with a wooden spoon. Stir in the flour, then the stock, tomato paste, mushrooms and black pepper and cook for 20 minutes.
  • Preheat the oven to broil. Ladle the soup into oven-safe bowls, then float a couple slices of baguette on top. Sprinkle evenly with Parmesan cheese then a handful of shredded Gruyere or Swiss. Place in the oven and broil until the cheese is browned and bubbly. Serve immediately.
Course Soup
Cuisine American, Western, Western Americana
Keyword acorn soup, Jackie Alpers, mushroom soup,, onion soup, The Unofficial Yellowstone Cookbook

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