Make the Teriyaki Sauce: In a small saucepan, combine the low-sodium soy sauce, mirin, brown sugar, toasted sesame oil, minced garlic, and grated ginger. Whisk to combine and bring to a gentle simmer over medium heat for 2-3 minutes.

Thicken the Sauce: In a small bowl, whisk together the cornstarch and cold water to create a smooth slurry. Slowly pour the slurry into the simmering sauce while whisking constantly. Cook for 1-2 minutes until the sauce thickens. Remove from heat.

Prepare the Salmon: Pat the salmon fillets completely dry with paper towels and season lightly with salt and pepper.

Sear the Salmon: Heat avocado oil in a large non-stick skillet over medium-high heat until shimmering. Place salmon in the pan, skin-side down (if applicable), and sear without moving for 4-5 minutes until a crust forms.

Flip and Glaze: Flip the salmon and reduce heat to medium-low. Pour about half of the teriyaki sauce over the fillets. Cook for another 3-4 minutes, spooning the pan sauce over the top, until the salmon is cooked to your liking (130°F for medium).

Assemble and Serve: Divide cooked rice and steamed broccoli among four bowls. Top each with a salmon fillet. Drizzle with remaining teriyaki sauce and garnish with sesame seeds and green onions.