Directions

1. Preheat oven to 425.
2. In a large pot over medium heat, add the pancetta, cook until dark pink and slightly crispy, about 6 minutes. Remove from pan with a slotted spoon, drain on a stack of paper towels. Add the butter and the onions to the pancetta fat in the pan, reduce heat to medium, and cook until onions have caramelized, stirring occasionally, about 15 to 20 minutes (don’t cook on too high heat or the onions will burn before they caramelize).
3. Place mushrooms on a rimmed baking sheet, toss with olive oil, salt and pepper. Roast for 8 minutes, toss and roast for an additional 8 minutes or until dark brown.