Begin by rinsing the mushrooms under cold water to remove any dirt. In a large pot, add enough water to just cover the mushrooms and pour in the white wine vinegar. Bring to a boil over medium-high heat.

Once boiling, cover the pot and let the mushrooms cook for 5 minutes.

Carefully drain the mushrooms in a colander to remove excess liquid. Transfer the mushrooms to a large mason jar.

In a separate bowl, whisk together the olive oil, minced garlic, chopped parsley, minced shallot, fresh lemon thyme, dried oregano, ground pepper, and salt.

Pour the marinade over the hot mushrooms in the mason jar. Seal the jar tightly and give it a gentle shake.

Allow the marinated mushrooms to cool to room temperature, then refrigerate for up to a week.