Step 1Mix the spices and grind them in batches in an electric spice or coffee grinder as finely as possible. In a small bowl, stir together the ground spices and enough water to make a stiff paste; we used about 3 tablespoons. You will have more achiote paste than is called for in the recipe. Store it well-wrapped in plastic in the freezer.
Step 1In a food processor or blender, blend the mayonnaise, garlic, oil, lime juice, salt and chipotle peppers. You will have more chipotle mayonnaise than is called for in the recipe. Keep in the refrigerator until ready to use.
Step 1In a small bowl, combine the garlic, salt and achiote paste. Put the mixture into a 1-gallon sealable plastic bag with the fish. Refrigerate for an hour.
Step 2On a cast-iron griddle or in a frying pan, heat the olive oil over medium-high heat. Scrape some of the extra achiote paste from the yellowtail, then grill the fish, about 6 to 8 minutes per side, or until done. If the fish is cooking too quickly or unevenly, adjust the heat as necessary. Let the fish rest for a few minutes before slicing it thinly across the grain; if the fish breaks apart, that's fine.
Step 3Warm the tortillas on a pan over medium heat; place on a platter or individual plates, two per person.
Step 4Divide the fish among the tortillas and top with shredded cabbage and a teaspoonful of chipotle mayonnaise. Serve immediately, with lime wedges.