Preheat the oven to 400°F (200°C).
In a mixing bowl, toss the cauliflower florets with vegetable oil, salt, and pepper until well coated.
Spread the cauliflower florets on a baking sheet and bake for 20-25 minutes or until they are lightly browned and crispy.
In a mixing bowl, whisk together the vegetable broth, soy sauce, hoisin sauce, and cornstarch until well combined. Heat the vegetable oil in a large skillet or wok over medium-high heat. Add the garlic, ginger, and red pepper flakes and sauté for 1-2 minutes.
Add the sauce to the pan and stir until it thickens.
Add the roasted cauliflower, peanuts, and green onions to the pan and stir until everything is coated in the sauce.
Serve hot with steamed rice.