Heat the oil in a large skillet or wok over medium-high heat.
Add the ground beef and cook for about 5-7 minutes, breaking it up with a wooden spoon until browned. 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 minced ginger, mixed bell peppers, broccoli, and snap peas. Cook for another 5 minutes, stirring frequently until the vegetables are tender but crisp.
Pour in the soy sauce and, if using, sprinkle the cornstarch. Mix well to combine. Season with salt and pepper to taste. Cook for an additional 2 minutes.
Serve hot over cooked brown rice or quinoa, if desired.
Feel free to swap the vegetables based on your preference or what you have on hand.
This dish pairs well with a sprinkle of sesame seeds or green onions for an additional flavor boost.
Leftovers can be stored in an airtight container in the refrigerator for up to 3 days.