Note: I used sour cream here, but you could use plain Greek yogurt as well, which is what I'll probably use in the future. I was making this for a crowd, so I doubled the amounts below, but there was not a single strand of asparagus left. If you're serving more than four, I'd suggest doubling it as well.
For the salad:
1 bunch of asparagus
3 oz. prosciutto
3 oz. parmesan, shaved
For the dressing:
1/2 c. sour cream or yogurt
Zest and juice from one lemon
2 T. whole-grain mustard
1 T. heavy cream
Salt and pepper to taste
1. Shave the asparagus very thinly with a mandolin or vegetable peeler. You will end up with ribbons of asparagus and whole tips. Thinly slice the prosciutto and separate into strands.
2. In a large bowl, combine the asparagus, prosciutto and parmesan.
3. In a small bowl, whisk together the dressing ingredients. Season to taste.
4. Pour the dressing over the salad ingredients and toss gently to combine. Refrigerate for half an hour or so to let the asparagus soften a bit.