Clean and wash mushrooms, and add to a pot. Fill enough water to cover the mushrooms. Add 1/2 cup of vinegar to the water, bring it to a boil and cook for 15 minutes. When mushrooms are cooked, drain the liquid and set aside.
Drain liquid and set mushrooms aside.
Into a separate pot, place water, salt, sugar, bay leaves and peppercorns, and bring it to a boil. Once the sugar and salt has dissolved, add 6 tbsp vinegar to the ingredients, then remove from heat and set aside.
Dice up garlic and place in mason jars, along with additional fresh herbs, and chili flakes. Fill up each jar with mushrooms and marinade. Cover and store for up to a month.