Preheat skillet over medium heat. When several drops of water sprinkled in skillet skitter and dissipate, approximately 7 - 9 minutes, add the onion and garlic, jalapeno, cilantro, tomatoes and lime juice.
Insert Utility Rack over the vegetables.
Season fish fillet with salt and pepper, add to the Utility Rack and cover.
Cook for approximately 7-10 mins until fish begins to flake.
Remove fish and add to the skillet. Mix well to combine the flavors with the fish.
Heat tortillas on a griddle.
Fill tortillas with fish mixture and top with cabbage, avocado, cilantro and a squeeze of lime. (salsa if desired)
Serve warm with a side of spanish rice.