Piquillo peppers, from northern Spain, are red and smoky-sweet. When stuffed with shrimp salad, they make a flavorful appetizer.
Heat 1 tablespoon oil in a saute pan over medium-high heat. Season shrimp with salt and pepper. Add to pan, and saute until golden and cooked through, about 3 minutes. Finely chop shrimp, and transfer to a bowl.
Prepare an ice-water bath. Bring a small pot of water to a boil. Add tomato, and cook until skin loosens, about 1 1/2 minutes. Using a slotted spoon, transfer to ice-water bath until cool enough to handle, about 1 minute. Peel tomato, cut into quarters, and remove and discard seeds. Finely chop tomato.
Heat remaining tablespoon oil in pan over medium heat. Add onion and garlic. Cook, stirring occasionally, until soft, 5 minutes.
Stir tomato into onion mixture, and cook for 2 minutes. Remove pan from heat; pour in sherry. Return to medium-high heat for 1 minute. Stir tomato mixture into shrimp, and season with salt and pepper. Let cool.
Stir in mayonnaise. Stuff each pepper with shrimp salad.