Heat a drizzle of olive oil in a skillet over medium-high heat. Season the cod evenly on both sides with paprika and chili powder.
Add the cod to the hot skillet and cook for 6–7 minutes per side, or until the fish is opaque, flakes easily with a fork, and is lightly golden on the outside. Remove from the skillet and break into large chunks.
While the fish cooks, whisk together the sour cream, lime juice, and chopped cilantro in a small bowl until smooth. Set aside.
Warm the corn tortillas in a dry skillet or microwave until soft and pliable.
Assemble the tacos by adding chunks of cod to each tortilla, topping with shredded red cabbage, and drizzling with the lime-cilantro sauce.