This is one of those suppers that is reasonably balanced, but brings the smugness of both ease and comfort. The sweet Riesling, once evaporated and thickened, coupled with the gentle anise flavor of the tarragon, transforms the vegetables entirely.
You may notice we don’t add any salt here. The reduced wine has such a startling body to it—and the prosciutto is salty enough—that additional salt would be overkill. But, your palate, your preference.
9 ounces asparagus spears
6 ounces baby leeks
Scant 1 cup Riesling wine
5 sprigs of tarragon
8 strips prosciutto
Generous ½ stick unsalted butter
Coarse black pepper
Trim the woody ends off the asparagus spears. I hold the root end in one hand, halfway up the stalk with the other, then gently bend it until it snaps. Wherever it breaks tends to be just about right. Rinse both the asparagus and the leeks, and dry completely with a clean kitchen cloth.
In a large, shallow Dutch oven—one you have a lid for—heat half the butter over medium-high heat. Once melted, add the asparagus and leeks, and fry, turning once, for a few minutes until gently colored. I’m not bothered that the butter might burn here; in fact, those nutty qualities will enhance the dish.
When the vegetables are colored, pour in the wine, and throw in the tarragon with a pinch of pepper. Pop on the lid, reduce the heat to fairly low, and simmer for 10 minutes. Once the wine has reduced almost entirely, and the vegetables are soft but offer a gentle resistance, the dish is ready. Add the remaining butter in cubes and allow it to melt over the vegetables. Serve the asparagus and leeks with pieces of prosciutto draped in and among.