Savory-sweet ground beef in a glossy soy glaze over rice, done in about 20 minutes. Lean 96/4 beef keeps a bowl at 42 grams of protein; scallions and sesame carry what the missing fat would.
Cook the rice according to package directions. Start it first so it lands when the beef does.
Whisk the soy sauce, brown sugar, oyster sauce, rice vinegar, ground ginger, and cornstarch until completely smooth — the cornstarch has to dissolve in the cold liquid or it will lump in the pan. Check that the vinegar bottle says unseasoned; the seasoned kind carries added sugar and salt and throws the balance off. Hold the sesame oil for the end.
Heat the neutral oil in a large skillet over medium-high. Spread the beef into an even layer and leave it alone for 3–4 minutes to build a brown crust, then break it into small pieces and finish cooking — 96/4 goes from done to dry quickly, so pull it a touch early; it finishes in the sauce.
Push the beef to one side of the pan and cook the grated garlic on the bare surface for 30 seconds, until fragrant. This takes the raw sharpness off — don't dump it straight into the liquid.
Pour the sauce over the beef and stir to combine. Simmer 2–3 minutes, stirring occasionally, until it thickens, turns glossy, and coats the meat.
Off the heat, drizzle in the sesame oil and stir — simmering would cook off the nutty aroma it's there for. Serve over rice, topped with the scallions and sesame seeds; with lean beef and a sweet sauce they're doing real work, not garnish.