01 - Melt butter in a large skillet over medium heat. Add finely chopped onion and sauté until translucent, approximately 3 minutes.
02 - Add minced garlic and sliced mushrooms to the skillet. Cook, stirring occasionally, until mushrooms are browned and tender, about 8 minutes.
03 - Sprinkle flour evenly over the cooked vegetables. Stir to coat and cook for 1 to 2 minutes to eliminate the raw flour taste.
04 - Slowly pour in the vegetable broth while stirring constantly to prevent lumps from forming.
05 - Add milk, soy sauce, Worcestershire sauce, dried thyme, dried sage, and black pepper. Stir thoroughly to combine.
06 - Bring the mixture to a gentle simmer. Cook, stirring occasionally, until the gravy thickens to the desired consistency, approximately 5 to 7 minutes.
07 - Taste and adjust salt as needed. Serve hot over mashed potatoes, roasted meats, or vegetables.