Preheat oven to 450ºF. Trim the bottoms of the asparagus spears at the point where they turn pale and tough. If the spears are medium to thick, peel the lower 2/3 of the trimmed spears with a sharp vegetable peeler. Thin spears do not need to be peeled. Place them in a bowl and toss with the chopped sage, olive oil and a light sprinkle of salt. Spread the asparagus in a single layer on a baking sheet and roast until the spears are slightly limp when you hold them from the bottom, 4-8 minutes depending on their thickness. They will continue to cook once you remove them from the oven. Let cool.
Heat the oil in a 1 1/2 - 2-quart saucepan. Drop in half of the sage leaves and turn them in the oil with a wire skimmer or slotted spoon. They'll sizzle loudly at first, but if they're dry, they won't splatter. Fry for only 10 to 15 seconds, then remove them to paper towels to drain. Do not let the leaves brown. Fry the remaining sage leaves and sprinkle them all lightly with salt. They should crisp when they cool. The sage can be fried up to 1 day ahead of time; it will stay crisp if stored in an airtight container at room temperature.
Hold a wedge of Parmigiano in your hand and use a sharp vegetable peeler with light pressure to shave thin curls of the cheese into a bowl. You'll want to shave off 2 ounces, about 1 cup.
Combine all the dressing ingredients except the olive oil in a small mixing bowl, then whisk in the oil.
Assembling the salad:.
When ready to serve, toss the asparagus with the dressing in a large bowl. Arrange the asparagus in a fan shape on a serving platter or individual plates. Sprinkle with the Parmigiano shavings and then with the fried sage leaves. If you have a sage plant that's flowering, sprinkle the salad with some of its blossoms.
Warm Roasted Asparagus with Sage Butter:.
Roast the asparagus spears as directed. While they are roasting, melt 4 tablespoons unsalted butter in a small (8-inch) skillet over medium-low heat. Add the 30 sage leaves and cook, stirring often, until the butter begins to brown slightly and the sage gives off a nutty, toasty aroma, 3 to 4 minutes. Stir in the finely sliced zest of 1 lemon, 3 tablespoons lemon juice, and 1/4 teaspoon salt. Transfer the asparagus to a warm platter and spoon the sage leaves and lemon butter on top. Sprinkle with the Parmigiano shavings and sage blossoms if available.