Lightweight and elegant, this pretty pink and green presentation makes a fine starter for a multicourse meal. Since chances are good that you’ll be in an Asian market for the loofah, pick up fresh water chestnuts there as well.
1tablespoon thin-sliced ginger
3scallions (green onions), white and green parts sliced and separated
3tablespoonsdry or medium-dry sherry
1teaspoon grated lime zest
½pound shelled shrimp
1cup peeled, sliced water chestnuts (fresh or canned)
4 comparatively straight loofahs (1½ to 2 inches in diameter and about 1 foot long)
Combine sliced ginger, white part of scallions, salt, sherry, cornstarch, egg, pepper, zest, and half the shrimp in food processor. Whirl to a fine puree. Scrape into a bowl.
Place water chestnuts and scallion greens in processor; chop fine. Add remaining shrimp and pulse to a coarse texture. Add to bowl and blend thoroughly. Chill. (Can be prepared a day ahead.)
With swivel peeler, zip fins from loofahs. Trim stem ends and halve each crosswise. With zucchini or apple corer (see Note), remove central pith, leaving a thin layer of flesh. Stuff with shrimp mixture.
Set loofahs on steamer rack over boiling water. Cover and steam until filling is firm and squash just tender, about 10 minutes.
Meanwhile, prepare sauce: Combine tomato puree, lime juice, 1½ tablespoons sugar, 1 tablespoon vinegar, cornstarch, sherry, water, butter, and 1 teaspoon ginger in small pan. Cook over fairly low, heat, stirring often, until mixture boils up and thickens. Add remaining ½ teaspoon ginger and stir a moment longer. Taste and add vinegar, salt, and sugar as needed.
To serve, cut each loofah section into 4 or 5 slices. Spoon ¼ cup hot sauce onto each individual serving plate. Divide slices among the plates. Sprinkle with optional cilantro and scallion.