Marinate Steak: In a mixing bowl, combine vegetable oil, sesame oil, soy sauce, brown sugar, minced garlic, grated ginger, and black pepper. Whisk together until the sugar dissolves. Add the flank steak, ensuring it is submerged in the marinade. Cover and let marinate in the refrigerator for at least 30 minutes, or up to 2 hours for deeper flavor.

Prepare Spicy Cream Sauce: In a small bowl, mix together mayonnaise, sriracha, lime juice, honey, and salt. Stir until well combined and creamy. Adjust the heat by adding more sriracha if desired. Set aside.

Cook Steak: Heat a grill pan or skillet over medium-high heat until hot. Remove flank steak from marinade, letting excess drip off. Cook for 4-5 minutes on each side for medium-rare. Once cooked, transfer to a cutting board and let rest before slicing thinly.

Assemble Bowls: Cook jasmine rice according to package instructions. In each serving bowl, add jasmine rice, top with sliced steak, chopped green onions, shredded carrots, and cucumber slices. Drizzle with spicy cream sauce.