Begin by heating 3 tablespoons of butter in a large, heavy-bottomed pot over medium heat until it starts to foam. Add in a diced yellow onion and 2 minced garlic cloves, cooking for about 4-5 minutes until the onion becomes translucent and fragrant.

Next, stir in 8 cups of mixed mushrooms, including Cremini, Shiitake, and Button, cooking them for 8-12 minutes until they are golden brown.

Pour in 4 cups of low-sodium vegetable broth and 1 teaspoon of dried thyme into the pot. Bring the mixture to a gentle boil, then reduce the heat and let it simmer uncovered for 15 minutes.

After simmering, remove the pot from heat and let it cool for 2-3 minutes. Using an immersion blender, blend the soup partially, leaving some chunky bits for texture.

Return the blended soup to low heat and stir in 1 cup of cottage cheese, blending until it becomes smooth and creamy. Season with salt and freshly cracked black pepper to taste.

Ladle the warm soup into bowls and garnish with freshly chopped parsley for a touch of color and freshness.