Ingredients
7 large oranges
2 pounds white asparagus, trimmed and peeled
Salt and freshly ground black pepper
2 tablespoons white-wine vinegar
4 tablespoons cold unsalted butter, cut into small pieces
Leaves from 4 stems fresh tarragon
Preparation
Juice 5 oranges over a sieve, yielding about 1 1/2 cups. Zest 1 orange. Using a paring knife, remove skin, pith, and outer membrane from remaining orange. Carefully cut each segment away from white membranes. (This is called supreming the orange). Set segments aside.
Place asparagus in a large saute pan. Add 1/2 inch of water, and bring to a boil. Lower heat, and steam asparagus to tenderize, about 8 minutes. Just before asparagus are fully cooked, drain liquid from the saute pan. Add 1/4 cup orange juice, and simmer until the asparagus are fork-tender. Remove from heat. Season with salt and pepper. Cover, and steam while finishing sauce.
Meanwhile, in a small saucepan, bring 1 1/4 cups orange juice to a boil. Add vinegar, lower heat, and simmer until reduced to 1/3 cup. Remove from heat, and stir in butter, one piece at a time, until sauce is thick and creamy. Season with salt and pepper. Transfer asparagus to a warm platter, drizzle with sauce, and garnish with reserved orange segments, zest, and tarragon.
