Prep your base: Cook rice or warm cauliflower rice.
Keep it fluffy and ready so the beef goes straight on top.
Make the sauce: In a bowl, whisk 1/3 cup low-sodium soy sauce, 2–3 tablespoons brown sugar, 2 teaspoons rice vinegar, 1/2 cup beef broth, 1 tablespoon cornstarch, 3–4 minced garlic cloves, 1 tablespoon grated ginger, and a pinch of red pepper flakes. Set aside.
Brown the beef: Heat 1 teaspoon avocado oil in a large skillet over medium-high. Add 1 pound lean ground beef.
Break it up and cook until browned with crisp edges, about 6–8 minutes. Drain excess fat if needed.
Add veggies: Stir in 1–2 cups chopped broccoli and 1 cup shredded carrots. Sauté 3–4 minutes until tender-crisp.
If using quick-cook veggies like snap peas, add them last for 2 minutes.
Pour in the sauce: Give the sauce a quick stir, then add it to the skillet. Toss to coat the beef and vegetables. Simmer 2–3 minutes until glossy and slightly thickened.
Finish with aromatics: Turn off the heat.
Stir in 1 teaspoon sesame oil and 3 sliced green onions. Taste and adjust with more soy for salt, vinegar for brightness, or red pepper for heat.
Assemble the bowls: Scoop rice into bowls, top with the Mongolian beef mixture, and sprinkle with sesame seeds. Add extra scallions or a squeeze of lime if you like.