For the shrimp: Heat the olive oil over high heat in a large pan. Season both sides of the shrimp with chili powder and salt to taste. Place the shrimp in a single layer in the pan and sear for 2-3 minutes per side, until shrimp are pink and cooked through.
For the mango salsa: Combine all the ingredients in a bowl, add salt to taste. Cover the bowl and place it in the refrigerator for at least 15 minutes, up to 4 hours.
For the creamy cilantro sauce: Place all ingredients in the food processor; process until sauce is smooth and creamy. Add salt and pepper to taste.
To serve: Warm the tortillas. Add a spoonful of sauce, a handful of cabbage and place the shrimp on top of the cabbage. Top with mango salsa and serve immediately.