In a large skillet or wok, heat the vegetable oil over medium-high heat. Add the ground beef and cook until browned, breaking it apart with a spatula, about 5-7 minutes. Drain excess fat if necessary.

Add the sliced onion and minced garlic to the skillet. Sauté for 2-3 minutes until the onion is translucent.

Stir in the bell pepper, broccoli, and snap peas. Cook for an additional 4-5 minutes until the vegetables are tender-crisp.

In a small bowl, whisk together the soy sauce, maple syrup, grated ginger, sesame oil, and red pepper flakes. Pour the sauce over the beef and vegetable mixture, stirring to combine. Cook for another 2-3 minutes to heat through and allow the flavors to meld.

Season with salt and pepper to taste. Serve hot over cooked rice or noodles.