From colored surfaces of orange and lime, grate enough of the orange peel to make 1 teaspoon.
From center of orange and lime, cut 1 or 2 thin crosswise slices apiece; wrap slices airtight and chill. Ream 3 tablespoons juice from orange, 1 tablespoon juice from lime. In a bowl, mix orange and lime peel, orange and lime juice, sour cream, and pepper. Makes 1 1/4 cups. Serve, or, if made ahead, cover and chill up to a day.
Bring 1 1/2 to 2 inches water to a boil in a 10-12" frying pan over high heat. Add asparagus and cook, uncovered, until stems are just tender to pierce, 5-7 minutes.
Drain asparagus well, then place hot spears on a warm platter; garnish with reserved orange and lime slices. Offer flavored sour cream and salt to add to taste.
Roxanne E. Chan, Albany, California.