01 -
Melt butter in a large stock pot over medium heat. Add chopped onion, carrot, and celery. Cook, stirring occasionally, until the vegetables become translucent, approximately 5 minutes. Stir in minced garlic, chopped mushrooms, and thyme, and continue to cook for 3 minutes.
02 -
Pour in vegetable stock and beef stock. Add Worcestershire sauce, a dash of red pepper flakes, salt, and black pepper. Stir thoroughly to combine all ingredients.
03 -
Reduce heat to low and allow the soup to simmer gently for 30 minutes, partially covered. Stir occasionally and monitor for even cooking.
04 -
Taste and adjust seasoning as necessary. Ladle the hot mushroom soup into bowls and serve immediately.