Step 1

Preheat oven to 400 degrees.

Step 2

In a food processor or blender, combine all ingredients except mushrooms and balsamic vinegar and blend until smooth.

Step 3

Wash mushrooms, carefully remove stems to create a pocket for the filling, and brush with balsamic vinegar. Evenly divide filling among mushrooms.

Step 4

Place stuffed mushrooms on a cookie sheet and bake for 10-15 minutes, until mushrooms have softened and released their moisture. Remove from oven, carefully use tongs or a spatula to transfer mushrooms to serving dish, and top with chopped bell pepper.