Cut filet, zucchini, broccoli, and onion into bite-sized pieces.

Heat oil in a pan, sear filet pieces until browned, then remove.

Stir-fry onion, zucchini, broccoli, and water chestnuts until just tender.

Return filet to pan, add teriyaki sauce, and toss to coat.

Serve over rice and sprinkle with sesame seeds.