3 tablespoons butter
1 small onion, thinly sliced
1-1/2 teaspoons kosher salt or to taste
1-1/4 pound asparagus ends or whole asparagus
2/3 cup dry white wine or vermouth
3 cups chicken stock
1/2 cup cream
1/4 teaspoon white pepper
Whenever we buy asparagus, we snap off the woody ends but we don’t throw them away. Rather, we save them up in the freezer until we have a bag full, and then we make soup. The ends have tons of flavor, but also lots of tough fiber, so you’ll definitely need to strain this soup. It’s worth the trouble. (You can certainly make this with a bunch of whole asparagus, in which case we suggest cutting off a few of the tips and steaming them for a garnish.)
In a large, heavy bottomed pot, melt the butter over medium low heat. Add the onion slicess and sprinkle with salt. Stir until coated with the butter. Cook for about 5 minutes, stirring occasionally, until softened.
Add the asparagus and wine, and bring to a simmer. Cook, stirring occasionally, for 5-7 minutes, until most of the wine evaporates. Add the chicken stock and simmer, covered, for an additional 20 to 35 minutes, or until the asparagus is very soft. Remove from heat and let cool slightly.
Pour about half the soup into a blender and puree until smooth. (Be careful to hold the lid on firmly, and don’t fill the blender more than about half full; divide into three batches if necessary.) Pour the soup into a bowl through a medium sieve, using a spatula to push the soup through. Discard the pulp. Repeat with the remaining soup.
Return to the pot and bring just to a simmer. Add cream and white pepper, and stir to combine. Adjust salt, if necessary.