In a medium bowl, whisk together vegetable oil, sesame oil, soy sauce, brown sugar, minced garlic, grated ginger, and black pepper. Marinate the flank steak for at least 30 minutes or overnight for deeper flavor.

Cook the jasmine rice according to package instructions until fluffy and tender. While cooking, chop green onions, shred carrots, and slice cucumber.

In a small mixing bowl, combine mayonnaise, sriracha sauce, lime juice, honey, and salt. Whisk until the sauce is smooth and creamy.

Heat a large skillet over high heat for 2-3 minutes. Sear the marinated steak for 3-5 minutes on each side until dark crust forms.

Let the steak rest for 5-10 minutes before slicing it thinly against the grain.

Assemble bowls by adding rice, topping with sliced steak, garnishing with green onions, carrots, and cucumber, and drizzling with creamy sriracha sauce.