First, if you are using frozen shrimp, thaw them by running under cold water and pat dry. Remove all the tails prior to cooking the shrimp. Chop the pineapple and avocado into small chunks.

In a large saute pan, heat the oil over medium heat. Then add the cajun seasoning, salt and cayenne pepper if you really like spicy. Swirl or stir to combine the oil and seasoning. Cook the shrimp in the spicy oil until fully cooked, about 2 minutes per side until the shrimp are pink and opaque. Remove from heat and transfer the shrimp to a bowl or plate. You can sprinkle with additional salt to taste if you would like.

Assemble the tacos. Spoon the shrimp onto the tortillas, then top with the pineapple and avocado. Garnish with fresh chopped cilantro and serve with lime wedges on the side.