Make Creamy Lime Sauce: Mix together yogurt and mayo. Stir in lime juice. Stir in cumin, dill, and cayenne. If desired, add a dash of salt and black pepper to taste. Set sauce in the fridge (make ahead for flavors to meld.)
Follow directions for Beer Battered Fish.
Warm-up tortillas to soften. Assemble fish tacos, with desired garnishes and creamy sauce while fish is crispy and hot!