How to Make It
In a medium bowl, whisk all of the ingredients until well blended.
Light a grill. In a large bowl, toss the asparagus, tomatoes, zucchini, avocados and oil; season with salt and pepper. Grill over moderately high heat until tender, 2 minutes for the asparagus and avocados and about 5 minutes for the tomatoes and zucchini. Cool.
Arrange the greens on a platter. Drizzle with 3 tablespoons of the vinaigrette and top with the hazelnuts. Serve with the grilled vegetables and the remaining vinaigrette.