Heat the water (or broth) in a frying pan over medium heat. Add the onion and garlic and cook until softened, about five minutes.
Add mushrooms. Cook for an additional 15 minutes, stirring occasionally.
Meanwhile, toast the walnuts by placing them in a small, dry frying pan on the stove over medium heat until just browned. Keep an eye on them so that they do not burn.
To the frying pan mixture, add the thyme, sage, nutritional yeast, Bragg’s Liquid Aminos and balsamic vinegar. Allow the mixture time to cook down, about five minutes, then turn off heat.
Transfer the mushroom mixture and toasted walnuts to a food processor, adding fresh ground pepper. Pulse until the mixture becomes a creamy pate. Do not over mix.
Serve at room temperature with crackers, bread or crostini. Alternatively, hollow out raw mushroom caps and fill with the pâté.