For a fish taco with fresh, bold flavors, we looked to the Yucatán Peninsula and the Pacific Coast for inspiration and fired up the grill. For simplicity we opted for skinless fillets instead of the traditional whole butterflied fish, and meaty swordfish held up better on the grill than flaky options like snapper and cod. Citrus-heavy marinades added little flavor and caused the fish to stick to the grill grate. A thick paste featuring ancho and chipotle chile powders, oregano, coriander, and just enough citrus juice to make it spreadable worked much better, developing deep, flavorful charring on the grill without promoting sticking. Refreshing grilled pineapple salsa, avocado, and crunchy iceberg lettuce completed our perfect grilled swordfish tacos.