After preparing the fish, season with salt and fry the bangus until the skin is crispy and the meat is golden. Flake the fish using two forks then cut the skin into small pieces with a scissor. Set aside.
Using the same pan, fry the chicken liver until cooked through. Let cool down completely then slice into small cubes.
In a bowl add flaked bangus, chicken liver, chicharon, onion, chili, mayonnaise, soy sauce, and lemon juice. Toss until all ingredients are combined. Season with salt and pepper according to preference.
Heat sizzling plate on a stove. When hot enough, melt 2 tbsp. butter. Transfer bangus sisig in the sizzling plate and serve. Bon appetit!