I'm guessing on the amounts - just go with it and smell, taste, etc. That's how he developed it.
Mix 2 tbsp soy sauce, less than 1/4 tsp sesame oil, dash of rice vinegar.
Put the fish on foil, curling up the edges.
Pour the mixture over the fish, then top with about a teaspoon or more of chili-garlic paste.
Close up the foil, creating a pouch, and grill for 6-7 minutes.
Remove from the grill, carefully opening the pouch.
Top with chopped green onions and serve.