Clean mushroom caps with a damp paper towel. Cut off stems from mushroom caps; rinse under cold water. Coarsely chop stems and set aside. Use a spoon or paring knife to scrape out and discard gills from mushroom caps. Brush 2 teaspoons of the oil over mushroom caps; place oiled sides down on a 15 x 10 inch jelly roll pan or baking sheet.
Heat remaining 1 tablespoon oil in a nonstick skillet over medium-high heat. Add asparagus, shallots, garlic and chopped mushroom stems. Cook 5 to 6 minutes or until vegetables are crisp-tender, stirring occasionally. Remove from heat; stir in tomato, salt and pepper. Spoon mixture into mushroom caps. Combine bread crumbs and cheese; sprinkle evenly over mushrooms. Bake 10 to 12 minutes or until hot and crumbs are golden brown. Yield: 4 servings (serving size: 1 stuffed mushroom cap).
*To make fresh bread crumbs, tear 1 to 2 slices multigrain bread into pieces and process in a food processor until coarse crumbs appear. Extra bread crumbs may be placed in a food storage freezer bag and frozen up to 3 months.
This was delicious and pretty quick and easy. I also used whole wheat panko instead of my own breadcrumbs. Served with cauliflower gratin with tomatoes, capers & feta (recipe from Vegetarian Times). I was first planning just a salad, but I think a more substantial vegetable made more sense.