Heat a large skillet over medium high. Add a drizzle of oil and brown the ground beef, breaking it up.

Season with a pinch of salt and pepper.

When the beef is mostly cooked and the moisture cooks off, push it to the sides.

Add a bit more oil if needed and toss in the onion, garlic, and ginger. Stir until fragrant, about a minute.

Add the chopped vegetables. Stir often, letting them sear a bit while still staying crisp.

In a small bowl, whisk soy sauce, oyster or hoisin if using, rice vinegar, sesame oil, brown sugar, and a touch of heat.

Pour it into the pan and toss to coat everything.

Let it simmer for a minute to thicken slightly. If you like saucier stir fry, splash in a tablespoon of water or broth.

Taste and adjust. Add a little more soy for salt, vinegar for brightness, or sugar for balance.

Top with sliced green onions and sesame seeds. Serve over hot rice or noodles.