In a mixing bowl, whisk together soy sauce, sesame oil, brown sugar, minced garlic, and grated ginger until combined. Coat the flank steak evenly in this marinade, ensuring every surface is well covered. Allow it to marinate in the refrigerator for at least 30 minutes.

While the steak marinates, cook jasmine rice according to package instructions. Bring water to a boil, add the rice, reduce heat to low, cover, and let simmer for about 15-18 minutes. Once cooked, remove from heat and fluff the rice with a fork.

In a separate bowl, combine sour cream, Sriracha, lime juice, honey, salt, and pepper to create your spicy cream sauce. Mix well until smooth.

Preheat a grill pan over high heat. Remove the steak from the marinade and place it on the grill pan. Grill for 5-6 minutes per side for medium-rare.

Once cooked, transfer the steak to a cutting board and let it rest for about 5 minutes.

In the same grill pan, add vegetable oil and let it heat briefly. Add mixed vegetables and sauté for approximately 5-7 minutes until they are tender yet crisp.

In serving bowls, layer cooked jasmine rice as the base. Slice the rested steak and arrange it atop the rice, followed by the sautéed vegetables.

Drizzle the spicy cream sauce over the assembled bowls and sprinkle with sesame seeds and chopped green onions.