In a 1 ½- to 2-quart enameled or stainless-steel saucepan, combine the vinegar, whole cloves, water, peppercorns, bay leaf, and salt.
Bring to a boil over high heat, drop in the mushrooms, and reduce the heat to low.
Simmer uncovered, for 10 minutes, stirring the mushrooms occasionally, then cool to room temperature.
Remove garlic from marinade and pour entire contents into a sealable jar. Slowly pour veggie oil on top into jar.
Seal jar, store in fridge for 1 week before opening