In a medium pot, cook the white rice according to the package directions.
In a medium saucepan, combine soy sauce, rice vinegar, ketchup, honey, sesame oil, light brown sugar, garlic paste, ginger paste, and chicken broth. Whisk together and bring to a boil.
In a small separate bowl, combine cornstarch and water. Whisk until no lumps remain.
Once the sauce is boiling, slowly whisk in the cornstarch mixture. Turn heat to low and let simmer while you prepare the cauliflower. Stir occasionally.
In a large skillet over medium, heat vegetable oil until it is about 2 inches deep. Turn heat to medium and let sit until the temperature reaches 350°F. It’s important that you test the temperature with a meat thermometer. If it’s too hot, it will burn the exterior of the cauliflower.
In a large bowl, combine flour, cumin, chili powder, coriander, onion powder, and black pepper. Whisk together. In a separate bowl, add the buttermilk.
Work in batches to cook the cauliflower in the following order: Take the 1-inch cauliflower pieces and dip them in the flour mixture. Then dip them in the buttermilk. Then dip them back in the flour mixture. Tap the excess flour off of the cauliflower pieces and add to the hot oil.
Cook the cauliflower on both sides for 5 to 7 minutes. Remove the cauliflower from the oil and place it on a paper towel-lined plate.
When all the cauliflower is cooked, place it in a large mixing bowl. Pour the hot sesame sauce over the top of the cauliflower. Use tongs or a large spoon to “toss” the cauliflower with the sesame sauce.
Serve over white rice and garnish with green onions and toasted sesame seeds.