Wash and dry all produce. Peel mango, then remove flesh from pit; discard pit. Cut into thin slices, then cut slices into skinny matchsticks. Halve lime.

Place mango, cabbage, and a squeeze of lime juice in a medium bowl. Season with salt and pepper. Toss to combine, then set aside.

Set aside 1/2 tsp Southwest spice in a small bowl. Season tilapia all over with salt, pepper, and remaining Southwest spice. Sprinkle with a drizzle of olive oil. Rub seasonings into fish until moistened.

Heat a drizzle of oil in a large pan over medium-high heat (use a nonstick pan if you have one). Add tilapia and cook until opaque and flaky, 3-4 minutes per side.

Meanwhile, add sour cream and a pinch of chipotle powder to bowl with reserved Southwest seasoning. Season with salt, pepper, and more chipotle powder (to taste). Stir in water 1 tsp at a time until mixture is a drizzly consistency.

Wrap tortillas in a damp paper towel and microwave on high until warm, about 30 seconds. Break up tilapia into bite-sized pieces and divide between tortillas. Top with slaw (you may not use all). Tear cilantro leaves from stems and scatter over. Drizzle with crema. Serve with any remaining slaw on the side.