Mix in 1 cup of teriyaki sauce and salmon in a resealable plastic bag. Squeeze air out of the bag and let it sit for 1-2 hours. Drain and discard used marinade.

Set oven rack about 4 inches from the heat source and preheat the oven's broiler. Place salmon steaks into a broiler pan and broil for 5 minutes. Brush steaks with more teriyaki sauce, turn, and broil until fish is opaque and flakes easily, about 5 more minutes. Brush again with marinade and sprinkle with sesame seeds.