Roughly chop the mushrooms and shallots, into a large dice. Try to keep them around the same size but it doesn't need to be perfect!
In a dry, cold pan, add the mushrooms. You may need to do this in 2 pans to avoid overcrowding. Bring the heat up to medium and stir the mushrooms occasionally. They will release a lot of water.
After about 10 minutes, the mushrooms should have released all their water. Just keep an eye on them, and once they have sweat it all out, add a little cooking oil and then the shallots. Stir to coat and cook until the shallots have softened, about 6 - 8 minutes.
Add in the garlic, stir and cook for 1 minute. Then add in the veggie stock, soy sauce, miso paste, and vegan worcestershire. If desired, add a couple sprigs of rosemary and / or thyme. Cook and reduce the stock until it's been absorbed, about 10 more minutes.
If using, remove the fresh herb sprigs, and add the mushroom mixture to a food processor along with the vegan butter and process until it's a smooth pate. Taste and adjust for seasoning. If it needs more umami, you can add 2 - 3 Tbsp of Nutritional Yeast. Enjoy with crackers as well as a Banh Mi! Store in the fridge for 4 - 5 days.