5 pounds asparagus trimmed cut into 2-inch pieces (14 to 15 cups)
1 tablespoon tarragon fresh minced
1 small garlic clove minced
4 cups leeks white green chopped ( and pale parts only; 4 large)
4 teaspoons lemon zest finely grated
6 cups low-salt chicken broth ()
0.3 cup olive oil
2 tablespoons parsley fresh italian minced
Equipment
bowl
baking sheet
ladle
oven
pot
blender
Directions
Preheat oven to 425°F.
Combine asparagus, leeks, and oil in very large bowl; toss to blend. Divide between 2 large rimmed baking sheets.
Sprinkle with salt and pepper. Roast vegetables until asparagus pieces are soft and leeks are golden, stirring occasionally, about 45 minutes; cool on sheets.
Spoon 1/3 of vegetables into blender; add 2 cups broth. Blend until smooth.
Transfer to large pot. Repeat 2 more times, using half of remaining vegetables and 2 cups broth for each batch. Warm soup over medium heat, thinning with more broth by 1/2 cupfuls, if desired. Season with salt and pepper. DO AHEAD: Can be made 1 day ahead. Cool slightly. Cover; chill. Rewarm before continuing.
Mix parsley, lemon peel, tarragon, and garlic in small bowl for gremolata.
