Butterfly the Shrimp:

1. Peel and devein the shrimp with a small sharp knife. Butterfly the shrimp by cutting along the back, halfway through. Arrange the shrimp on a large platter. Sprinkle with the minced jalapeno and the chopped cilantro. Pour the lime juice over them and let marinate for at least 30 to 40 minutes, refrigerated. When you are ready to cook, season them lightly with salt.

Prepare the Batter:

2. In a small bowl, sift together the flour and baking powder. Whisk in the ice water until the batter is smooth, then add the remaining ingredients, seasoning with the cayenne and salt to taste. Place the small bowl in a slight larger bowl full of ice to keep the batter ice cold. This ensures crisp tempura.

3. At serving time, in a deep, heavy saucepan, wok or deep-fat fryer, heat 3 inches of oil to 350 degrees.

4. Dip each shrimp into the batter and coat well. Carefully place three or four at a time into the hot oil and cook until they are golden brown, about 2 minutes. Remove with a slotted spoon or flat strainer and drain on paper towels. Keep warm while preparing the remaining shrimp and the spinach.

5. In the same oil, cook the spinach leaves. Drain on paper towel and season ever so lightly with salt. Arrange a few fried spinach leaves on each plate with 3 shrimp on top.

                       SERVE IMMEDIATELY.