In a large bowl, whisk together vegetable oil, sesame oil, soy sauce, brown sugar, minced garlic, grated ginger, and black pepper to create a marinade. Add the flank steak, ensuring it's coated, then cover and marinate for at least 30 minutes in the refrigerator.

While the steak marinates, combine mayonnaise, sriracha, lime juice, honey, and a pinch of salt in a small bowl. Whisk until smooth and refrigerate.

Heat a grill pan or skillet over medium-high heat. Remove steak from marinade and cook for about 4–5 minutes on each side for medium-rare. Transfer to a cutting board.

Let the steak rest for 5 minutes, then slice against the grain into thin pieces.

Assemble bowls starting with jasmine rice, then add sliced steak, followed by green onions, carrots, and cucumber.

Drizzle the spicy cream sauce over the assembled bowls and serve immediately.