Step 1

Sprinkle fish evenly with chili powder and pepper. Heat oil in a large nonstick or cast-iron skillet over medium-high heat. Add the fish; cook until golden brown and cooked through, about 3 minutes per side. Transfer to a paper-towel-lined plate; sprinkle evenly with 1/4 teaspoon salt. Set aside.

Step 2

Place avocado, yogurt, water, lime juice and the remaining 1/4 teaspoon salt in a blender; process until well combined and smooth, about 30 seconds.

Step 3

Use a fork to flake the fish into large pieces. Top tortillas with the fish, jicama, the avocado sauce, sliced chile (or jalapeño) and cilantro. Serve immediately.