Heat a large dutch oven over medium/high heat and add olive oil.
When the olive oil is fragrant, add the mushrooms and a 1/8 teaspoon of salt to the pot and turn heat down to medium heat.
Let the mushrooms cook for 7-9 minutes in order to sweat out their liquid, stirring occasionally.
Next, add white onion, shallot and garlic to the pot and let sauté for 3-4 minutes.
After cooking the vegetables down, deglaze the pot with vegetable broth, salt, pepper, and add the herb bundle to the pot.
Mix, and turn heat to high and bring to a boil.
Once boiling, turn heat down to low and let simmer for 30 minutes, uncovered.
Once the mushroom gravy has reduced after 30 minutes, remove herb bundle and discard.
Then, add the tapioca flour to the gravy by slowly sprinkling into the pot while whisking constantly.
Once thickened, remove from heat and serve over vegetables or any protein.