From Seaforager.com

For the tacos:

Chilipepper rockfish
Ground cumin
Sea salt and freshly ground black pepper, as you like it
Fresh corn tortillas

For the fish taco sauce – stir together:

Equal parts plain yogurt & mayonnaise
Juice from ½ a lemon or lime
½ tsp cumin
a couple dashes of Tapatío hot sauce

For the Mexican slaw:

½ head red or green cabbage, chopped
1 bunch of scallions, chopped (red onion is good too, if that’s easier)
1 red bell pepper, chopped
1 jalapeno, remove the ribs and seeds and chop it  
1 can (or fresh if you’ve got it!) corn, rinsed
½ a bunch (or more!) of cilantro, chopped

Dressing:

olive oil & red wine vinegar & lime or lemon juice & 1 tsp cumin & a few dashes of Tapatío hot sauce. Toss in a big bowl, let sit for at least 10 min, toss from time to time.

Directions

Before you cook the fish, assemble your Mexican slaw so that it can settle into a groove with the dressing while you prepare the rest.
Chop up that onion, sautee it in a small pot with those 2 cloves of garlic.  After a few minutes, add the rinsed black beans and let them cook on low. Several dashes of tapatío would not be remiss here.
Fire up the broiler and crack open a Mexican beer while it gets going. Lightly oil a baking sheet and lay your beautiful rockfish fillets down on it.  Sprinkle fillets with salt & pepper & broil until lightly browned for 5 to 8 minutes, until the fillets are white and firm (but don’t overcook!)
While your fish are cooking, mix up your fish taco sauce: combine your yogurt, mayo, lemon/lime juice, cumin and stir until smooth.