Heat a skillet over medium heat and cook the burger patties until browned on both sides and fully cooked through. Set aside to rest.
In a separate pan, heat a little oil and sauté mushrooms and onions until soft and lightly caramelized. Add teriyaki sauce and let it simmer for 1–2 minutes until glossy and coated.
In another pan, heat oil and stir-fry the cooked rice with diced vegetables for 3–5 minutes until warmed through and slightly crisp.
Fry the eggs to your liking (sunny-side up or over-easy works best here).
Assemble bowls by layering veggie rice, then teriyaki mushrooms and onions, followed by the burger patty. Top with a fried egg.
Garnish with scallions, sesame seeds, chili flakes, or extra sauce if desired. Serve warm.