Make Salsa: Combine Mango Avocado Salsa ingredients in a large bowl. Taste and add additional salt, lime or cilantro - as desired. Set aside.
Make Slaw: Add mayo, lime juice and white wine vinegar to a medium bowl. Stir to combine. Add cabbage, cilantro and pinch of salt. Toss to combine. Taste and add additional salt, lime or cilantro - as desired. Set aside.
Prep Grill: Ensure grill grates are clean and preheat grill to 400-450 degrees F.
Prep Foil: If you are using aluminum foil - take a large piece to create a little grill mat out of it by folding up the sides. Ensure it is big enough to hold all of your fish fillets.
Prep Tilapia: Place tilapia fillets on a plate or baking sheet. Season generously with salt and pepper. Set aside.
Make Garlic Butter: combine butter and garlic in a small bowl. Set aside.
Grill Tilapia: Place aluminum foil on the hot grill and place the fish fillets (flat side up) over direct heat. Close the grill. Let cook approx. 2 minutes 30 seconds. Open the grill and use a fish spatula to gently flip the fish over. Place a dollop of garlic butter on top of each fillet and close the lid again. Let the fish cook for approx. 2 minutes or until the fish is fully cooked.
Build Tacos + Serve: Transfer fish to a plate and let cool slightly. Flake fish apart into small, bite-sized chunks. Build a taco by placing a street taco tortilla on a plate, top with some slaw, then fish chunks, and then some salsa. Top with a little extra cilantro and fresh lime juice, if desired. Serve immediately.
Notes
Gluten-Free: to make this gluten-free use a gluten-free tortilla (reg. or street taco size).
Other Fish: you can definitely switch up the type of fish you use here, but I would recommend sticking with a lighter white fish that doesn't have TOO strong of a natural flavor. Cod fillets would work really well too.