Marinated mushrooms are perfect for party platters and charcuterie boards, but they also make a lovely savory snack. Try them with steak or chicken too!
In a Dutch oven or large pot, bring 8 cups water and 2 tablespoons salt to a boil. Add mushrooms and cook until tender, about 3 to 4 minutes. Remove mushrooms from water and drain well.
Meanwhile, in a large bowl, whisk together olive oil and white wine vinegar. Stir in red onions, garlic, sugar, oregano, peppercorns, red pepper flakes (if using), and bay leaf. Stir in mushrooms, coating well. Season to taste with salt and freshly ground black pepper.
Transfer mushrooms to an airtight container. Chill for at least 5 minutes, best if chilled 8 hours or overnight. Remove bay leaf and serve garnished with fresh parsley.
Notes
Mushrooms: I love the flavor of cremini mushrooms, but white button mushrooms or baby bellas are fine too. If the mushrooms are small, you don't need to cut them in half.
Red onion: Or substitute 1/4 cup minced shallot.
Oregano: Or substitute 1 1/2 teaspoons minced fresh oregano.
Crushed red pepper flakes: These are optional, but I love the kick just a pinch adds to these mushrooms.
Yield: This recipe makes about 4 cups marinated mushrooms, enough for 4 as a side dish or more as part of an antipasto platter.
Storage: Store covered in the refrigerator for up to 4 days.
Make ahead: While they can be eaten after just 5 minutes of chilling, these mushrooms are best made ahead and chilled for at least 8 hours. Make them up to 3 days ahead, especially for parties and holidays when you're way too busy anyway.
Canning: Because mushrooms are a low-acid food, these marinated mushrooms are not safe for home canning.