Preheat the oven to 425F convection or 450F regular bake. Line a baking sheet with parchment paper.
Cook the rice (instructions here). To a medium bowl, add sugar, soy, gochujang, sesame oil, and garlic. Mix with a fork to combine. Add the chicken, 1 cup scallions (save the rest for topping), and ½ teaspoon salt. Use your hands to mix until thoroughly combined. Form into 8 large meatballs (I like to divide the meat in the bowl into quarters, then each quarter becomes 2 meatballs to give you 8).
To the baking sheet, add the veggies, olive oil, and remaining ½ teaspoon salt. Toss to coat, then spread out into an even layer. Nestle the meatballs into the veggies. Bake for 20-30 minutes or until the veggies are charred and meatballs are cooked through and browned on top.
To a jar with a lid, add the sauce ingredients and shake vigorously until combined (it should be very runny). If too thick, add a bit more water and shake again. If too thin, add a bit more tahini and shake again.
Serve the meatballs/veg over warm rice. Drizzle the sauce all over and top with the remaining scallions and sesame seeds. Cut up your meatballs and dig in!