The first hints of spring have finally arrived here this week, but there's still plenty of snow left in the shady spots. This soup is perfect for this transitional time of year, combining the delicate flavor of spring vegetables with a rich, creamy base. Go easy on the seasonings here; the asparagus is the real star of this dish.
1 lb. fresh white asparagus
2 T sugar
Salt, to taste
12 tbsp. butter, divided
2 T fresh lemon juice
12 T flour
¼–½ cup heavy cream (optional)
Bring twelve cups of water to a boil in a medium pot over high heat. Meanwhile, trim off the bottom ½" of the asparagus. Peel the skin from each, starting 1½'' from the top and running the length of the spear. Reserve peels. Gather spears into 2 bundles and tie loosely with kitchen string.
When water in pot comes to a boil, reduce heat to medium. Add the reserved peels, sugar, 1 tsp. salt, 3 T butter, and lemon juice. Return to a simmer, then add asparagus and cook until tender, 8-30 minutes, depending on thickness of asparagus (test by piercing with the tip of a knife held perpendicular to the length of the stalk). Remove asparagus from pot and drain on paper towels, then set aside. Increase heat to medium-high and reduce stock by one-third, about 30 minutes. Strain stock and keep hot over low heat.
Melt the remaining 9 T butter in a large saucepan over medium-low heat. Add flour and cook, stirring with a wooden spoon, for two minutes, do not brown. Whisk in hot asparagus stock 1 cup at a time and continue whisking until smooth. Simmer soup, stirring often, until thickened, about 15 minutes. If desired, add cream to taste and continue simmering for 2 minutes more. Season to taste with salt and a little more lemon juice or white wine, if you like.
Untie asparagus bundles, then cut spears into 1'' lengths and add to soup. Simmer until spears are warmed.