Mix the sauce: In a small bowl, whisk together soy sauce, brown sugar, minced garlic, and grated ginger until the sugar dissolves fully. Set the sauce aside near the stove so it's ready to pour.

Heat the skillet: Set a large skillet over medium-high heat and add the vegetable oil. Wait until the oil shimmers slightly before adding the beef, so the meat sizzles on contact.

Brown the beef: Add the ground beef and break it into small, uneven crumbles with a wooden spoon. Let it cook undisturbed for 30-second stretches so the edges turn deep brown, about 6 to 8 minutes total.

Drain excess fat: Tilt the skillet and spoon off any excess fat pooling at the bottom. This keeps the finished sauce from turning greasy instead of glossy.

Add the sauce: Pour the prepared sauce over the browned beef and stir well so every crumble gets coated. The sauce should start bubbling almost immediately.

Simmer to a glaze: Let the mixture bubble gently for 2 to 3 minutes, stirring occasionally, until the sauce thickens and clings to the beef rather than pooling in the pan.

Add heat (optional): Stir in red pepper flakes if you want extra spice. Taste the beef and adjust with a splash more soy sauce if needed.

Finish with sesame oil: Remove the skillet from heat and drizzle in the sesame oil, stirring to combine. The aroma will turn noticeably nuttier right away.

Warm the rice: While the beef simmers, warm the cooked rice in the microwave or a separate pot so it's hot and ready for serving.

Assemble the bowls: Divide the rice among four bowls and spoon the glazed beef on top, dividing evenly.

Garnish and serve: Scatter sliced green onions over each bowl for color and a fresh bite. Serve while the beef is still glossy and warm.