Preheat oven to 425 degrees F. Line a 15x10x1-inch baking pan with foil. Remove stems from mushrooms and discard or save for another use. Place mushroom caps, stem sides down, in prepared pan. Lightly coat the rounded side of each mushroom cap with nonstick cooking spray. Bake about 5 minutes or just until tender. Carefully place mushroom caps, stem sides down, on a double thickness of paper towels to cool.Advertisement
Meanwhile, in a small bowl, combine sour cream, carrot, sweet pepper, green onion, garlic, salt, and the dash black pepper. Place cooled mushroom caps, stem sides up, on a platter. Spoon a scant tablespoon of the sour cream mixture into each mushroom cap. Top each with a broccoli floret. If desired, sprinkle with additional black pepper. Serve immediately.