1 Rinse asparagus and cut off the woody ends. Peel the lower third of spears (if desired), then cut into piecces. Pierce eggs and hard-boil in a small pot of boiling water for 8-10 minutes.
2 Cook asparagus in a pot of boiling (lightly) salted water, covered, until crisp-tender, 5-8 minutes. Remove asparagus from water with a slotted spoon, drain and let cool.
3 Finely grate Parmesan cheese.
4 Rinse the eggs under cold running water, peel and allow to cool.
5 Place yogurt in a bowl. Stir in 1 tablespoon asparagus cooking water, the Parmesan cheese and mustard. Season with salt and pepper.
6 Rinse scallions, shake dry, cut into thin rings and add to the dressing.
7 Rinse lettuce and radicchio, spin dry and cut into bite-sized pieces.
8 Mix salad and asparagus with yogurt dressing and divide among bowls or glasses. Cut the eggs into quarters, arrange on the salad and serve.