Preheat oven to 425F and line a sheet pan with aluminum foil for easier cleanup; set aside.
In a bowl combine soy sauce, garlic, honey, brown sugar, sesame oil, rice vinegar, ginger and whisk to combine.
Add the steak, stir to combine, and let it marinate for 10 to 15 minutes (up to 1 hour, even better).
Using a tongs transfer the steak to the sheet pan with space in between the pieces; set aside.
Add the broccoli to the marinade to coat, stir and using slotted spoon, transfer to the baking sheet along with the beef.
Roast for about 10 to 12 minutes, or until the steak is cooked through and the broccoli is fork-tender.
While the food bakes, optionally, add the reserved marinade to a small saucepan and bring it to a boil over medium-high heat.
Add the cornstarch and cold water to a small bowl, stir to combine, add to the boiling saucepan, whisking until dissolved. The sauce will get very thick quickly because there’s not much quantity. If desired, add about 1/4 to 1/2 cup water as desired for consistency, whisking until incorporated and smooth.
After the beef and broccoli are done, evenly drizzle with the sauce, to taste.
Garnish with sesame seeds, ( and optional green onions, chopped) and serve immediately.