½ C. (1 stick) unsalted butter
2 large yellow onions, coarsely chopped
4 large cloves garlic, coarsely chopped
1½ Qt. chicken stock
3 lb. asparagus
1 bunch fresh parsley, stems removed, chopped (1 C.)
2 medium-size carrots, peeled, cut 1” pieces
8 fresh large basil leaves
1 T. dried tarragon
1 t. salt
1 t. freshly ground black pepper
pinch cayenne pepper
1 C. sour cream
1 ripe tomato, seeded, diced small
Melt butter in a heavy saucepan over low heat. Add onions and garlic. Cook uncovered until wilted, about 25 minutes. Add stock and heat to boiling.
Trim woody ends from asparagus and cut stalks into 1” pieces. Reserve the tips, add asparagus pieces, parsley, carrots, basil, tarragon, salt, pepper, and cayenne to the stock. Reduce heat to medium-low and simmer covered until the vegetables are tender, about 50 minutes.
Remove the soup from heat and let cool. Process in batches in a blender or food processor fitted with a steel blade until smooth. Strain the soup through a medium-size sieve to remove woody fibers.
Return the strained soup to the pan. Add asparagus tips and simmer over medium heat until the tips are tender, about 10 minutes.
Ladle the soup into soup bowls. Dollop each serving with sour cream and sprinkle with diced tomatoes.
Makes 8 portions.