Process about 2 slices of whole wheat bread in a food processor. You can use prepared breadcrumbs, but whenever possible, use fresh. This makes about 1 1/2 cups of breadcrumbs. It's also a great way to use up the heels of your loaves. Set aside.
Remove stems from mushrooms and chop them up.
Brush one of the tablespoons of oil around in a 13x9 inch pan. Heat the rest of the oil in a pan over medium high heat. Add garlic and onions and sauté for 7 minutes.
Stir in salt, and then breadcrumbs, basil, and parsley. Evenly distribute mixture on to mushroom caps.
Bake for 30-45 minutes, depending on the size of your mushroom caps. Keep an eye out that they don't get too brown. Serve with a fresh salad, and enjoy!