In a mixing bowl, whisk together mayonnaise (or yogurt), taco seasoning, and fresh lime juice until well combined. Toss in shredded cabbage, carrots, green onions, and cilantro. Set aside a couple of tablespoons of the dressing for later use.

Pat the cod fillets dry and season with taco seasoning. Heat a skillet over medium-high heat, add olive oil, and cook the fillets for about 4 minutes on each side until gold and flaky.

In the same skillet, sauté diced red onion, bell pepper, and jalapeño for 1 minute. Stir in frozen corn and black beans, mix well, and squeeze fresh lime juice over the mixture.

To assemble, layer the slaw at the base of the bowl, spoon the vegetable salsa over it, add flaky cod on top, and garnish with avocado slices, lime wedges, and fresh cilantro.