Gluten Free Mushroom "Barley" Soup Recipe- With Buckwheat. Vegan Option

I grew up on mushroom barley soup. That is one of those foods that I consider to be a comfort food, evoking special warm feelings inside, of satiation, comfort, and love. I know- weird how something like certain foods affect us emotionally, but they do.
The thing is- I haven't been able to have mushroom barley soup for a good few years, since barley is gluten, and I've been off gluten over two years already. So I haven't been able to have one of my favorite foods.
Recently I discovered that raw buckwheat works as a replacement for so many different types of grains, and in this case- it works terrifically as a replacement for barley. As I said, it's been years since I had real mushroom barley soup, so I can't promise you that this tastes identical, but it's close enough that it really did the trick. If you aren't concerned about the gluten, feel free to replace the buckwheat in this recipe with pearl barley.
This soup was loved by everyone who ate it.

Gluten Free Mushroom "Barley" Soup Recipe- Made from Buckwheat, With Vegan Option

Ingredients:
2 tablespoons oil
1 large onion
3 carrots
1/4 cup celery leaves
1 can mushrooms- or approximately 1 1/2 cups of fresh mushrooms
7 cups broth (vegetable or chicken broth- both are fine. I use my scrap broth.)
1/2 cup untoasted buckwheat (this will be a light green/tan color, not brown) (you can use pearl barley instead but it makes the soup glutenous)
2-3 bay leaves
1/2-1 teaspoon garlic powder
Salt and pepper to taste

Instructions:
1. Heat the oil. Chop the onions. Saute the onions in the oil until starting to brown.

2. Dice the carrots finely, and add them to the onions. Saute until starting to soften.

3. Add the mushrooms and saute a few minutes further.

4. Add the rest of the ingredients, bring to a boil, and then simmer until everything is fully cooked and soft.

5. Adjust salt and/or pepper to taste.

Enjoy!

Have you ever eaten mushroom barley soup? Are you a fan? How do you make yours? Do you think you'd try this recipe with buckwheat to make it gluten free? Have you ever heard of any other gluten free mushroom "barley" soup recipes? What was in it instead of the barley?