Preheat the grill to medium. Brush the prepared vegetables on all sides with olive oil and season with garlic salt and black pepper.
Place on the grill cooking for 4 minutes on each side or until crisp tender.
Remove to a large platter in a single layer, to cool slightly.Don't stack. [Tip: If you stack the vegetables, they'll continue to steam and cook.]
To make the vinaigrette: Place the ingredients for the vinaigrette into a blender, reserving the oil. Pulse until combined.
Drizzle the oil in through the top of the blender on low speed and process until emulsified. This can be done up to 3 days in advance and refrigerated.
Shake well before serving. Yield: approximately ¾ cup
To assemble the dish: Remove the woody ends from the grilled asparagus and cut in half.
Cut the zucchini and squash into bite size chunks and slice the peppers.
Place onto a serving platter or into a bowl.
Drizzle the vegetables lightly with the vinaigrette, and sprinkle with crumbled cheese just before serving.
Serve the remaining vinaigrette on the side.
Garnish with ribbons of fresh basil.