Start by dicing the yellow onion and chopping the broccoli into bite-sized florets. Having everything ready to go will streamline your cooking process.
In a large skillet or wok, heat the sesame oil over medium-high heat. Add the lean ground beef and cook until browned, breaking it apart with a wooden spoon as it cooks. This should take about 5-7 minutes.
Once the ground beef is browned, add the diced onion, minced garlic, and minced ginger. Stir everything together and cook for an additional 2-3 minutes, until the onion becomes translucent and fragrant.
Add the chopped broccoli florets to the skillet. Stir to combine, ensuring the broccoli is coated in the beef mixture. Cook for about 5 minutes, or until the broccoli is bright green and tender-crisp.
In a small bowl, whisk together the soy sauce, hoisin sauce, and brown sugar (if using). Pour this mixture over the beef and broccoli in the skillet. Stir well to combine and let it simmer for another 2-3 minutes to allow the flavors to meld.
Taste the dish and adjust the seasoning if needed. If you prefer a bit more sweetness, add more brown sugar. If you like it saltier, a splash more of soy sauce can do the trick.
Once everything is well combined and heated through, remove the skillet from the heat. Serve the Easy Beef and Broccoli (with Ground Beef) over steamed rice or noodles for a complete meal.