Fish Tacos with Cabbage Slaw and Avocado Crema

Enthusiasts disagree about what makes the ultimate fish taco, but in its simplest form, this iconic dish consists of tender pieces of fish, a little dressed cabbage and a creamy dressing folded into a warm tortilla. Crema is a Mexican-style cultured cream similar to sour cream. Yogurt makes a good substitute, blending with avocado into a creamy sauce.