Baked Chestnut Pesto Portobello Caps

1. Preheat the oven to 400 degrees Fahrenheit. 2. Wipe mushroom caps with a damp cloth to remove and dirt and trim away mushroom stems. Brush mushroom caps with olive oil. 3. Arrange mushroom caps on a rimmed baking sheet, top side facing down. Roast until mushrooms begin to release liquid, about 10 minutes. 4. While the mushrooms are in the oven, prepare the pesto. In a food processor fitted with a multipurpose blade, combine chestnuts, pecorino cheese, parsley, thyme, sage, rosemary, garlic, lemon juice, salt, and ground black pepper. Pulse the pesto ingredients together until they are coarsely chopped. Add the olive oil and continue to process until the pesto comes together. The pesto should be thick and spoonable vs thin and saucy. If it’s too thick, add an extra drizzle of olive oil. 5. Add the breadcrumbs to the pesto and pulse to combine. 6. Remove the baking sheet from the oven. Use paper towels to blot up excess moisture the mushrooms release. Divide the pesto filling between the mushroom caps. Return mushrooms to the oven and roast until mushrooms are tender and filling is hot, about 15 minutes.