Prepare the rice following the package instructions.
Heat the olive oil and chili flakes in a large pan over medium heat. Sauté the diced onion until it becomes translucent.
Add the lean ground beef to the pan, breaking it apart with a sturdy spatula. Cook until the beef is fully browned with no pink visible, then stir in the minced garlic and season with salt and cracked pepper.
While the beef cooks, whisk together sriracha, maple syrup, tamari, and sesame oil in a small bowl to create the sauce.
Mix the kidney beans, diced zucchini, and red bell pepper into the beef mixture. Season again with salt and cracked pepper and cook until the vegetables soften.
Pour the prepared sauce over the beef and vegetables and stir thoroughly to combine.
Fold in the arugula or spinach along with the chopped cilantro and give everything a final mix. Taste and adjust seasoning as needed.
Scoop the cooked rice into serving bowls and top each with the beef and vegetable mixture to serve.