We have tweaked the tradition of this dish by adding the sweetness of roasted red peppers to it.
1/2 pound salt cod, thick middle cut
1 sweet red bell pepper (about 1/4 pound)
1/4 cup Spanish extra-virgin olive oil
2 small tomatoes (each about 1/4 pound)
1/4 cup firmly packed, extremely thinly sliced onion rings
2 teaspoons red-wine vinegar
1. Soak the salt cod for at least 24 hours (more, if it's especially salty) in several changes of cold water.
2. When ready to prepare dish, place the red pepper over an open flame and cook, turning, until charred on all sides. Place in paper bag and let rest for 20 minutes. Remove blackened skin, stem, and seeds. Cut pepper into long, thin strips. Reserve.
3. With a very sharp knife, cut the salt cod into very thin slices, approximately 1 inch by 1/2 inch by 1/2 inch. (It may shred as you cut; that's okay. Try cutting slices from all sides, to see which side yields the neatest slices.)
4. Toss slices with 2 tablespoons of the olive oil in a large bowl. Cut each tomato in half lengthwise, then, cut lengthwise into very thin slices. Add the tomato slices to the salt cod, and toss gently. Let rest for 10 minutes.
5. Just before serving, add the onion rings, reserved red pepper strips, and vinegar to the cod. Toss gently. Divide among 6 plates, and top each mound of esqueixada with a teaspoon of olive oil, or more to taste. Serve immediately.
Think of this fabulous Catalan dish as Spanish sashimi or Spanish carpaccio. The really neat and surprising thing, however, is that the raw flesh of choice is salt cod! You'll be delighted at how deliciously it blends with the traditional tomatoes, onions, red-wine vinegar, and olive oil. About the latter: make sure to use only the greatest, youngest extra-virgin Spanish olive oil you can find; we recommend Nuñez de Prado from Andalusia. About the salt cod: make sure to use the highest-quality, thickest, moistest salt cod you can find. We sell a terrific piece at the store that needs only 24 hours of soaking; if yours is saltier and drier, you might want to soak it for 48 hours. We have tweaked the tradition of this dish by adding the sweetness of roasted red peppers to it; you may leave them out if you wish a more austere creation. Either way, it's a great liftoff for a Spanish dinner party. Serves 6 as a small first course.