Snap off the thick ends of the asparagus, cut the spears diagonally into bite-size pieces, and blanch in lightly salted water. Drain and cool. Meanwhile, beat the butter until light and blend in the lemon zest; season to taste with salt and pepper. Preheat the oven to 450 degrees F. For each portion, fold a 12-inch square of baking parchment in half diagonally and crease the corners. Arrange one portion of tilapia filet on one side of the paper. Season with a little lemon juice and top with a quarter of the shrimp and asparagus. Dot with a quarter of the lemon butter. Fold the other side of the paper over the fish and seal the package into a half oval with a series of creases, starting with one corner and finishing with a twist at the opposite end. Repeat for the remaining portions. Bake the packages on a sheet pan until the paper is browned and puffy, 7 to 8 minutes. To serve, slit open each package and slide the contents, out onto a plate; or serve in the paper, letting each diner cut open his own. PER SERVING: 205 calories, 31 g protein, 2 g carbohydrate, 8 g fat (4 g saturated), 108 mg cholesterol, 38 mg sodium, 1 g fiber. Jay Harlow writing in the San Francisco Chronicle, 3/18/92. Posted by Stephen Ceideburg