1. Preheat oven to 450 degrees. Whatever kind of mushrooms you’ve selected, trim the stems and cut caps into approximately 1-inch pieces. Smaller mushrooms may be halved or left whole.
2. In a large baking pan combine mushrooms, onions, and garlic cloves. Drizzle with the oil and toss to coat well. Distribute evenly in pan.
3. Roast undisturbed for 10 minutes. Stir well, redistributing evenly and roast for ten minutes more.
4. Sprinkle walnuts over mushrooms and onions, add salt and pepper, and roast for 5 minutes more. Remove from the oven and let cool for a few minutes.
5. In a food processor, combine roasted vegetables and vinegar. Pulse until a coarse paste is formed, scraping down sides as necessary.

*Note- These mushrooms can also be found in dried form, to reconstitute them: rinse mushrooms, blanch in boiling water for 2-5 minutes, or soak 30 minutes in warm water.

Other delicious options: use a Toasted Walnut Grapeseed oil, or regular walnut oil with the pear vinegar.

Use pecans instead of walnuts and add Spicy Pecan Vinegar instead of Pear vinegar.