Whisk together the mayonnaise, lime zest, lime juice, and garlic powder in a small mixing bowl. Set aside.
Combine the Mrs. Dash Lemon Pepper and the salt in a small prep bowl.
Evenly coat the cod fillets with the lemon pepper mixture.
Heat a medium cast iron skillet over medium heat and spray with avocado oil spray.
When the skillet is very hot, add the cod fillets. If the skillet isn't hot enough, they will stick. Cook for 3-6 minutes per side, depending on thickness, until cooked through.
As the cod cooks, prepare your plates by layering on the romaine, cabbage, and onion.
When the fish is done cooking, add it to your prepared salad plates. Drizzle on the mayonnaise mixture and top with fresh cilantro (if using).
Store leftovers in separate containers (veggies, fish, dressing) in the refrigerator for up to 3 days.
Notes
I used Mrs. Dash Lemon Pepper because it is the only one I've found that contains neither sugar nor maltodextrin nor artificial colors. If you have a different lemon pepper seasoning that meets these requirements and it also contains salt, you can use that in place of the Mrs. Dash and omit the salt from the recipe.When purchasing mayonnaise, look for one with only healthy oils, like avocado oil, and no sugar. Avoid those with soybean oil, vegetable oil, canola oil, etc. Be sure to read the ingredient list, because even the ones that say avocado oil or olive oil on the front usually only have a small amount of the healthy oil and the rest is soy or canola. My favorite store-bought mayonnaises are Sir Kensington's Avocado Oil or Primal Kitchen.