1. To blanch asparagus, bring water to a boil and prepare an ice bath or very cold water separately. Drop the asparagus in the boiling water for only 2 min. Then remove and place in the ice bath; this will cease the cooking and result in bright green and crunchy vegetables. Remove from ice bath and pat dry with paper towel.
2. Mix dressing. In a small bowl, mash blue cheese and yogurt together with a fork. Stir in mayonnaise, lemon juice, vinegar, and garlic powder until well blended. Season to taste with salt and pepper. Note: I didn't have the 1tbsp white wine vinegar, so I used double the amount in regular white wine (2 tbsp). I also wanted the dressing consistency to be more runny, so I thinned it out with skim milk.
3. Assemble salad on a plate or platter. First, place shredded lettuce on the plate followed by evenly distributing the onion rings, radish slices, and tomatoes over top. Next, lay asparagus spears in a circular fashion (like in the photo) then top with prosciutto slices, walnut halves and crumbled blue cheese. Last, drizzle the dressing over top and voila!