In a medium bowl, whisk together vegetable oil, sesame oil, soy sauce, brown sugar, minced garlic, grated ginger, and black pepper until fully combined. Add the flank steak, ensuring it is well-coated in the marinade. Cover the bowl with plastic wrap and refrigerate for at least 30 minutes, or up to 2 hours.

In a small mixing bowl, combine mayonnaise, sriracha sauce, lime juice, honey, and a pinch of salt. Whisk together until smooth and creamy, adjusting the sriracha to your desired heat level. Set aside.

Preheat a grill pan over medium-high heat for about 5 minutes until hot. Remove the marinated flank steak from the refrigerator and place it on the grill pan. Cook for 4-5 minutes on each side until the internal temperature reaches 130°F for medium-rare. Let it rest for 5 minutes before slicing against the grain.

For each bowl, start with a scoop of cooked jasmine rice as your base. Slice the rested steak thinly and arrange it on top. Add green onions, shredded carrots, and cucumber slices for a fresh topping.

Drizzle the spicy cream sauce generously over the assembled bowls. Optionally, sprinkle with toasted sesame seeds before serving.