Combine onions, garlic, and olive oil in a large frying pan and sauté over medium flame until onions are tender and bordering translucent, stirring frequently, at least 10 minutes.
When onions are translucent, add the fresh herbs and the mushrooms. Stir to incorporate with the onion mixture, and allow to cook another five minutes.
Add cashews and give them a few minutes in the pan to marry flavors. When everything is soft, remove from heat and transfer mixture from the pan into a Vitamix or blender.
Add tamari, Braggs, and water to taste, then blend to incorporate. It may look thinner than you expect, but it will thicken as it cools. Adjust saltiness as desired with tamari and Braggs.
Serve with any main and side dishes—incredible with all veggies, potatoes, and anything else you can imagine slathering with gravy.