Bacalao is Spanish for dried salt cod; our version of the popular Caribbean dish is steepedfor several hours in a blend ofred wine vinegar, garlic, andtomatoes.
Put cod in a medium bowl. Cover with cold water. Cover with plastic wrap, and refrigerate at least 8 hours, or up to 2 days. Drain water from bowl. Cover cod with fresh water. Refrigerate, covered, at least 8 hours or up to 2 days. Drain. Rinse cod, and pat dry.
Heat oil in a large skillet over high heat. Add cod, onion, bell pepper, and garlic. Cook, stirring constantly, until onion and pepper have softened and cod begins to break up, about 6 minutes.
Stir in tomatoes. Reduce heat to medium. Simmer 10 minutes. Let cool completely. Stir in the vinegar and pepper. Refrigerate cod mixture at least 3 hours (or overnight). Season with salt, or drizzle with vinegar, if desired.
Arrange lettuce on a large platter. Spread cod mixture on top.