How to Make It
Heat oven to 400° F. Place the tilapia on a rimmed baking sheet and season with ¾ teaspoon salt and ¼ teaspoon pepper. Bake until cooked through, 10 to 12 minutes. Let cool and flake into small pieces.
In a medium bowl, combine the mayonnaise, eggs, dill, and 1 tablespoon of the mustard. Fold in the tilapia and panko. Form the mixture into 8 cakes and chill for at least 30 minutes. Heat the canola oil in a large nonstick skillet over medium heat. Cook the tilapia cakes until golden, 3 to 5 minutes per side.
Meanwhile, in a large bowl, whisk together the olive oil, vinegar, the remaining 1 teaspoon of mustard, ½ teaspoon salt, and ¼ teaspoon pepper. Add the salad greens and toss to combine. Serve with the fish cakes.