Food & Cooking Recipes Healthy Recipes Gluten-Free Recipes Roasted Mushrooms and Pearl Onions 3.6 (149) Close Use this recipe when making our Beef Bourguignon. Directions Preheat oven to 425 degrees. On a large rimmed baking sheet, toss mushrooms with onions and oil; season with salt and pepper. Roast until tender and browned, stirring halfway through, about 30 minutes.