Squish the bag to combine the ingredients. Remove excess air, seal, and freeze.
Thaw.
Preheat the oven to 425° and line a cookie sheet with parchment paper.
Open the bag and add 1/4 cup water and 1 Tbsp. corn starch. Reseal bag and mix gently to combine.
Transfer the beef and broccoli to the cookie sheet. Bake 10-12 minutes.
Garnish with chopped green onions and sesame seeds if desired.