What ingredient is NOT typically found in the fish taco build?

In the context of a traditional fish taco build, sour cream is not typically a standard ingredient. Fish tacos generally consist of a tortilla as the base, filled with fish, and often topped with slaw to add crunch and balance. The combination of the tortilla, fish, and slaw creates a harmonious blend of flavors and textures that are characteristic of this dish. While some variations might use sour cream or other sauces as a condiment, it does not form an essential part of the classic fish taco assembly. The primary focus is on the fresh elements of the fish and the slaw rather than creamy ingredients, distinguishing it from other types of tacos that may lean more towards creamy toppings.