Pat the shrimp dry. Sprinkle with Tajin seasoning. Heat a skillet and add the olive oil. Working in batches, add the shrimp to the hot oil in one layer. Cook 2 minutes on the first side, flip over and cook 2 more minutes. Remove to a plate as each batch is cooked.
When all the shrimp is cooked, add a little more oil to the pan. Quickly sauté the pineapple, red pepper, scallions, and lime zest in the same skillet until the pepper is very soft.. Add the lime juice and Worcestershire. Return the shrimp to the pan and continue to cook only long enough to reheat the shrimp. Taste and add more Tajin if needed.
Garnish with chopped cilantro if using. Serve with tortillas or over rice.
