Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper for easy cleanup.
In a large mixing bowl, combine ground beef or pork, breadcrumbs, chopped green onions, minced garlic, egg, soy sauce, sesame oil, ground ginger, salt, and pepper. Mix until well combined.
Form the mixture into golf ball-sized meatballs and place them on the prepared baking sheet.
Bake the meatballs in the preheated oven for 15-20 minutes, or until cooked through and browned on the outside.
While the meatballs bake, prepare the sauce. In a saucepan over medium heat, combine soy sauce, brown sugar, sesame oil, rice vinegar, minced ginger, and minced garlic. Bring to a simmer.
Once simmering, add the cornstarch mixture to the saucepan, stirring constantly until the sauce thickens (about 1-2 minutes). Remove from heat.
In a large skillet or wok, add olive oil and broccoli florets. Sauté over medium heat for about 5-7 minutes until the broccoli is bright green and slightly tender. Season with salt and pepper.
Once the meatballs are done, add them to the skillet with the broccoli. Pour the sticky sauce over the meatballs and broccoli, tossing gently to coat everything evenly.
Serve hot, garnished with additional green onions if desired.