Cream of Asparagus Soup
800 g green asparagus
1 large onion, chopped
2 tablespoons unsalted butter
5 cups vegetable stock
1/2 cup crème fraîche or heavy cream ( I used sour cream)
1/4 teaspoon fresh lemon juice, or to taste
salt and pepper
Cut tips asparagus. Reserve them for garnish.
Cut all remaining asparagus into 1/2-inch pieces.
Cook onion in butter over moderately low heat, stirring, until softened. Add asparagus pieces and salt and pepper to taste, then cook, stirring, 5 minutes. Add stock and simmer, covered, until asparagus is very tender, 15 to 20 minutes.
While soup simmers, cook reserved asparagus tips in boiling salted water until just tender, 3 to 4 minutes, then drain.
Purée soup in batches in a blender until smooth, transferring to a bowl (use caution when blending hot liquids), and return to pan. Stir in crème fraîche.Season with salt and pepper.
Add lemon juice and garnish with asparagus tips.