Heat oil in a large Dutch oven over medium-high heat. Add mushrooms and cook until they start to release their water and brown, 10-15 minutes.
4 tbsp Extra virgin olive oil, 1 lb Cremini mushrooms, 1/2 lb Shitake mushrooms
Add the celery, carrots, and onions and cook until softened, about 10 minutes. Add garlic and cook another minute.
2 ribs Celery, 3 medium Carrots, 4 cloves Garlic
Add the white wine, bring to a boil, and reduce for 2 minutes while scraping the bottom of the pot to remove all the flavor bits. Add the vegetable stock, bay leaves, and thyme. Bring to a boil, reduce the heat to a simmer.
1 cup Dry white wine, 10 cups Vegetable stock, 6 sprigs Fresh thyme, 2 large Bay leaves
Add the pearl barley, kosher salt, and black pepper. Simmer for 45-60 minutes, stirring occasionally to avoid sticking, until the barley is tender. Remove the bay leaves and thyme stems, season to taste with salt and pepper and serve.
1 cup Pearl barley, 1/2 tsp Kosher salt, 1/2 tsp Black pepper