Combine the fish and marinade ingredients in a large Zip-Loc bag and then place in the fridge for 30 minutes or up to three hours.
Meanwhile, prepare the chipotle cilanto lime ranch dressing if you haven't already (recipe here).
When you're almost finished marinading the fish, pre-heat over to 350F and wrap your tacos in foil. You can warm them while you're preparing the rest of the dish.
Prepare the coleslaw by mixing your red cabbage, corn, scallions, lime juice, olive oil, and salt & pepper. Set aside.
You can cook the tilapia a couple of different ways. I cooked mine on the BBQ (med. high heat, approx. 4 min. on each side), but it didn't taste drastically different or better than just frying it for a few minutes on each side (depending on thickness). When the fish is ready, it should easily flake with a fork.
Assemble tacos by adding the cabbage slaw, flaked fish, and chipotle dressing. Serve with extra lime wedges if desired.