Preheat your oven to 400°F (200°C).
In a bowl, mix together soy sauce, rice vinegar, orange juice, orange zest, brown sugar, garlic, and ginger.
Place the cauliflower florets on a baking sheet and pour the sauce over them, tossing to coat.
Roast in the oven for about 25-30 minutes, until cauliflower is tender.
In a small bowl, mix cornstarch and water to create a slurry.
Heat a pan on the stove over medium heat and add the roasted cauliflower and sauce.
Pour the slurry into the pan and stir until the sauce thickens.
Serve the orange peel cauliflower over cooked rice and garnish with chopped green onions.
