Add cubed sweet potatoes, carrots, and mushrooms to a saucepan with 2 inches of water. Bring to a boil, reduce to brisk simmer, cover and cook for approximately 10 minutes or until potatoes are slightly tender.
While the veggies are cooking, place the veggie broth, nutritional yeast, flour, curry powder, garlic powder, turmeric, ginger, miso, and cayenne pepper in a large pot and bring to a boil, stirring constantly. Immediately turn the heat to low and stir until the mixture thickens into a gravy.
Remove the sweet potatoes, carrots and mushrooms with a slotted spoon and add to the gravy. Do not discard the cooking water, it is very flavorful and a good addition if the vegetable liquid is low.
Add the black pepper and kale to the gravy and vegetable mixture, gently stir and simmer for about 4 minutes or until the kale is tender.
To serve, place a scoop of rice into individual bowls and top with the veggies and gravy, with the bright green broccolini nestled on top.