Combine rinsed rice and beef bone broth in a pot. Bring to a boil, then cover and simmer on low for 15 minutes. Remove from heat and let stand for 5 minutes.
Heat vegetable oil in a large cast-iron skillet or heavy-bottomed pan over medium-high heat.
Add the ground beef to the skillet. Season with salt and pepper. Cook until browned and fully rendered, breaking the meat into small granules.
Drain approximately 75% of the rendered fat from the pan, leaving enough to coat the bottom.
Reduce heat to medium. Add the minced garlic to the beef and sauté for 60 seconds until fragrant but not browned.
Add the unsalted butter and soy sauce to the skillet. Stir continuously until the butter is completely melted and emulsified with the beef juices.
Incorporate the cooked rice into the skillet. Use a folding motion to ensure the rice grains are evenly coated in the garlic butter sauce.
Garnish with chopped scallions and serve immediately.