While fish fillets are cooking, you can prep your ingredients for pico de gallo. Mix all ingredients in a bowl with a squeeze or two of lime and salt to taste. Set aside.
When your fish is done cooking, cut fillets in half so they fit into slider rolls.
Construct your Baja Fish Sliders: Bottom roll, fish fillet, cabbage, pico de gallo, crema, top roll. Use a toothpick if needed to keep the slider together. Garnish plate with chopped cilantro and a lime wedge.