Cut your white fish into small pieces (about 1 inch wide by 3 inches long). Drizzle the juice of 1 lime all over the fish then season with salt, pepper and chili powder to your liking. Let sit for at least 5 minutes.
Meanwhile prepare the white sauce by combining all the sauce ingredients in a bowl and whisk to combine. Set in fridge until ready to use.
Heat up your grill or grill pan to medium-high heat and brush with the canola oil to prevent sticking. When the grill or pan is hot, reduce heat to medium and cook fish for 2 to 3 minutes per side or until fully cooked. Fish should flake easily.
Place grilled fish onto prepared corn tortilla, add some white sauce, shredded cabbage, pico de gallo, and chopped cilantro. Serve with a lime wedge on the side. Enjoy!