Tilapia is grilled with butter, Old Bay seasoning, and garlic, and then set atop toasted multigrain bread with melted pepper jack cheese and a sauce of mayo, dill relish, red onions, tomato, and a piri piri kick.
Stir together the mayonnaise, onion, tomato, relish, and piri piri in a small bowl. Season to taste with salt and pepper, and set aside.
Season the tilapia fillets on both sides with the seafood seasoning and garlic powder. Melt the butter in a skillet over medium heat. Cook the tilapia fillets until they are golden brown on both sides and no longer translucent in the center, 2 to 3 minutes per side. Place two slices of pepperjack cheese on top of each fillet, cover the skillet, and cook until the cheese has melted.
Place each tilapia fillet onto a slice of toasted bread, spread with the reserved sauce, then top with the remaining slices of bread.
Per Serving: 798 calories; protein 43.7g; carbohydrates 31.5g; fat 55.3g; cholesterol 142.7mg; sodium 1307.6mg.