1. Heat the olive oil in a skillet over medium-high heat. Add the mushrooms and cook, stirring for about 1 minute, or until they begin to soften. Add the garlic, salt, and pepper and cook for 2 to 3 minutes, or until the mushrooms soften. Set aside to cool.
2. Combine the veal, parsley, cooled mushroom mixture, salt, and pepper in a large bowl. Using your hands, mix well. Form into 6 patties. Refrigerate until ready to grill.
3. Prepare a charcoal or gas grill. Lightly spray the grill rack with vegetable oil cooking spray. The coals should be modestly hot.
4. Grill the burgers for about 8 minutes. Turn and grill for about 6 minutes longer for medium-well burgers.