Adjust racks to top and middle positions and preheat oven to 425 degrees. Wash and dry produce.

Trim, peel, and cut carrots on a diagonal into ½-inch-thick pieces. Toss on a baking sheet with a drizzle of oil and a pinch of salt and pepper. 

Roast on top rack until browned and tender, 20-25 minutes.

While carrots roast, peel and mince or grate ginger. Trim and thinly slice scallions, separating whites from greens; mince whites.

Heat a drizzle of oil in a small pot over medium-high heat. Add half the ginger; cook until fragrant, 1 minute.

Stir in rice, 1¼ cups water (2¼ cups for 4 servings), and a pinch of salt. Bring to a boil, then cover and reduce heat to low. Cook until rice is tender, 15-18 minutes.

Keep covered off heat until ready to serve.

While rice cooks, in a large bowl, combine beef*, scallion whites, panko, remaining ginger, and 1 TBSP umami ginger sauce (2 TBSP for 4 servings). (You’ll use the rest of the umami ginger sauce in the next step.) Season with salt (we used ¾ tsp; 1½ tsp for 4) and pepper.

Form into 1½-inch meatballs and spread out on a second baking sheet.

Bake on middle rack until browned and cooked through, 14-16 minutes.

Meanwhile, in a small bowl, combine sour cream with Sriracha to taste. Add water 1 tsp at a time until mixture reaches a drizzling consistency.

Once meatballs are done, gently transfer to a second large bowl; add remaining umami ginger sauce and toss to coat.

Fluff rice with a fork; taste and season with salt if desired.

Divide rice between plates and top with carrots, meatballs, and any umami ginger sauce from bowl. Drizzle with creamy Sriracha. Garnish with scallion greens and as many sesame seeds as you like. Serve.