In large bowl, whisk together lime juice, oil, mustard and salt. Stir in cabbage, pineapple, green onions, jalapeño and cilantro until well coated. Let stand for 10 minutes.
Meanwhile, toss shrimp with oil, Cajun seasoning, salt and pepper.
Heat cast-iron or heavy-bottomed skillet over medium heat. Cook seasoned shrimp, flipping once, for 2 to 4 minutes or until golden and just cooked through. Squeeze lime juice over top.
Meanwhile, warm tortillas according to package directions.
Divide shrimp mixture among tortillas and top with pineapple coleslaw.
Tips: Add sliced avocado or guacamole to shrimp tacos if desired.
Use store-bought shredded cabbage or coleslaw mix for speedy preparation.