In a pot large enough to hold all the mushrooms, boil the cleaned and trimmed mushrooms in water for 3-4 minutes or until slightly tender. Drain and set aside.
Warm the oil in a pot on the stove and add the bay leaf, peppercorns, onion and garlic. You don't want to sizzle the veggies, just help release the flavor.
Pour the oil mixture into a bowl and add the herbs, mushrooms, vinegar, brown sugar substitute, and salt. Mix well.
Put into jars and store in the fridge. Enjoy!
Notes
The marinating liquid was not calculated in the nutritional info because you won't be eating it.