Wash and chop all vegetables and mince garlic.
Heat sesame oil in a skillet over medium-high heat and cook minced garlic for 30 seconds until fragrant.
Add ground beef, cook until browned, breaking into small pieces.
Stir in soy sauce, chili flakes, and brown sugar, simmer for 3 to 4 minutes until sauce thickens slightly. Remove from heat.
In another pan, heat olive oil, sauté garlic for 30 seconds.
Add mushrooms and cook for 2 minutes.
Add broccoli, zucchini, and red bell pepper; stir-fry for 4 to 5 minutes until tender-crisp.
Add soy sauce to the vegetables and toss well to combine.
To serve, place steamed rice in bowls and arrange beef and vegetables on top or side by side.
Spoon any remaining sauce over the bowl for extra flavor.