Preheat vegetable or peanut oil in a pot or deep fryter to 375ºF.

Meanwhile, purée piquillo peppers in a food processor, adding a small amount of water if necessary. Add mayonnaise; process until smooth. Season with Tabasco, salt, and pepper. Set aside.

For tempura batter, combine rice flour, soda water, and egg. Whisk until smooth. Keep on ice or in refrigerator.

Working in batches of 5 or 6, dredge shrimp in remaining rice flour, whisk tempura batter and immediately dip shrimp in batter; remove shrimp by tail and carefully dangle shrimp in the hot oil, swinging back and forth. After a few seconds, drip shrimp fully into oil. Continue frying for 2 to 3 minutes until shrimp are crispy and just cooked through. Season shrimp immediately with salt upon removing from il. Toss hot, crispy shrim with sauce, serve with a salad of fresh herbs and greens, dressed with olive oil, vinegar, and salt and pepper to taste.