Heat a 12" nonstick skillet over medium-high heat with 1 tablespoon of canola oil.
Pat the salmon filets dry with a paper towel, then season lightly on all sides with kosher salt.
Carefully place the salmon skin-side down in the skillet to crisp the skin, for about 5 minutes. Turn the salmon over using a fish spatula and reduce the heat to medium.
Cook for about 2 more minutes or until the internal temperature reaches 125° F for medium-rare or 130° F for medium. You can brush some of the teriyaki sauce on the salmon while to second side cooks to create a glaze.
Make the teriyaki sauce while the salmon cooks
Make the sauce (over medium-low heat) by bringing the brown sugar, soy sauce, garlic and ginger to a light boil.
In a small bowl, whisk with a fork the corn starch with the mirin. Add this mixture to the sauce, stir in and simmer over low heat until the sauce reaches the desired consistency, about 5 minutes.
Drizzle the teriyaki sauce over the salmon and warm through.
Garnish with sliced green onions and toasted sesame seeds.