These are GREAT!! They can be an appetizer or a good side dish paired with a steak.
Take large portobello mushroom caps and place upside down on a baking sheet. (You can remove stems if desired.) Drizzle each liberally with balsamic vinegar, and sprinkle with salt and pepper. Cover each with shredded asiago cheese. Top each with one slice of bacon, cut in half and criss-crossed. Bake at 350 for 25 minutes, or until bacon is done.