Whisk together, beer, flour and salt in a large bowl.
Heat 1 ½ inches of oil in depth in a large skillet over medium heat.
Dip fish pieces in batter, covering evenly. Working in batches, immediately transfer to hot oil. Fry for 2 minutes or until golden brown. Transfer to paper towel lined plate to absorb any excess oil.
Heat tortillas. Place a few pieces of fish, top with cabbage, tomato, cilantro a sprinkle of lime juice and a drizzle of chipotle crema.
Place all ingredients in a blender or food processor. Blend until smooth. Transfer to a serving bowl.