Step 1

Mix sour cream and lime juice together in a large bowl; season with salt and black pepper. Reserve about half the mixture in another bowl for serving. Mince half the jalapeno pepper; save other half for later. Toss cabbage, green onions, and minced jalapeno half in remaining sour cream mixture until slaw is well mixed.

Step 2

Heat olive oil and remaining jalapeno half in a large skillet over medium heat; swirl oil to coat skillet evenly. Season tilapia fillets with salt and pepper. Pan-fry fish strips in the skillet in 2 batches until fish is golden brown and easily flaked with a fork, 5 to 6 minutes. Discard jalapeno half.

Step 3

Heat tortillas in the microwave on high until warm, 20 to 30 seconds.

Step 4

Serve fish in warmed tortillas topped with cabbage slaw, reserved sour cream mixture, and cilantro.