This recipe has a video above for easy visual instructions.
Add dried mushrooms to a large pot or saucepan and pour in the vegetable broth. Bring to a boil and let cook for about 1 minute, then turn off the heat and set aside.
Heat oil in a large skillet or pot over medium heat, add onion and sauté for 2-3 minutes. Add garlic, thyme, rosemary, salt, black pepper and sauté for another 1 minute, stirring frequently.
Combine plant-based milk and cornstarch in a small bowl and stir with a whisk. Set aside.
Add the soy sauce and red wine (optional) to the skillet while stirring.
Next, add the rehydrated mushrooms with the broth and stir to combine. Also, add the plant-based milk/cornstarch mixture. Let the gravy simmer for about 5 minutes or longer if you want it to be even more flavorful and thick.
I used an immersion blender to blend the gravy, however, you can also transfer the gravy to a blender and blend until smooth. If the gravy is too thick, add more vegetable broth and if you want it to be thicker, simply add more cornstarch or arrowroot flour.
Taste and adjust seasonings. You can also add red pepper flakes for some heat. Reheat the gravy in a pan/skillet and serve over mashed potatoes, vegan meatloaf, vegan meatballs, etc.
Store leftovers covered in the fridge for up to 4 or 5 days. You can also freeze the gravy for up to 2 months.