Preheat oven to 425 degrees F. Scrub potatoes thoroughly; cut in half. In a 13x9x2-inch baking pan, toss potatoes with 2 tablespoons of the Fresh Herb Vinaigrette.
Roast potatoes in the preheated oven for 30 minutes, stirring once halfway through cooking. Meanwhile, wash asparagus. Break off woody bases where spears snap easily. Add the asparagus, tomatoes, and 2 tablespoons more vinaigrette to the pan with potatoes. Roast for 10 minutes more, stirring once.
To serve, arrange salad greens on a large platter. Arrange potatoes, asparagus, and tomatoes on top. Top with strips of prosciutto and shaved Asiago cheese. Serve with remaining Fresh Herb Vinaigrette. Makes 6 side-dish servings.
Fresh Herb Vinaigrette
In a screw-top jar, combine olive oil, white wine vinegar, red onion, fresh herbs, garlic, mustard, salt, and black pepper. Cover and shake well.