
To a small pot, add soy sauce, water, brown sugar, chili flakes, honey, garlic, ginger, sesame oil and mirin.
Bring to a quick boil, then reduce heat and simmer 3-4 minutes to thicken and allow the flavors to develop.
To thicken (if desired), swirl together cold water and cornstarch in a small bowl until you have a thin slurry. Pour into the pot and stir to incorporate. Continue to heat, stirring, until the sauce thickens.
Remove from heat, cool, and store in the fridge. Strain, if desired. Set aside.
Heat your grill to medium heat and lightly oil the grates. Alternatively, heat a grill pan to medium heat and add 1 tablespoon olive oil.
Season the salmon fillets with Chinese 5 spice (or your own preferred seasonings) and salt and pepper to taste.
Grill the salmon skin side down (if using skin-on salmon) for 4-5 minutes, then flip the salmon and grill flesh side down for another 4-5 minutes, or until cooked through to your preference.
Mop the Homemade Teriyaki Sauce over the salmon during the last minute of cooking.
Serve the salmon and drizzle with a bit more teriyaki sauce as desired. Garnish with chili flakes and sesame seeds.