Rinse the rice until the water runs clear. Put in a small saucepan with 250ml (1 cup) water, cover and bring to a simmer over medium heat. Reduce the heat to low and cook for 12 mins or until tender and the water is absorbed. Turn off the heat and stand, covered, for at least 5 mins. Fluff the rice with a fork.
Step 2 — Marinate beef
Meanwhile, combine the teriyaki sauce and 1 tsp sugar in a large bowl. Separate the beef stir-fry into the teriyaki mixture and toss to coat.
Step 3 — Pickle veggies
Cut the cucumber into short batons. Shred the carrot using a julienne peeler or coarsely grate with a box grater. Combine 2 tsp white vinegar and ½ tsp sugar in a large bowl and season with salt and pepper. Add the cucumber and carrot and toss to coat. Set aside to pickle, tossing occasionally, until needed.
Step 4 — Stir-fry beef
Heat 2 tsp vegetable oil in a medium frypan over high heat until very hot (see Kitchen 101). Stir-fry the beef, reserving the remaining marinade in the bowl, for 2 mins or until browned. Add the reserved marinade and 1 tsp soy sauce and bring to the boil. Cook, stirring, for 30 secs or until slightly reduced. Remove the pan from the heat.
Step 5 — Serve up
Divide the rice, beef and pickled veggies among bowls. Drizzle the veggies with any remaining pickling liquid. Dollop with the mayonnaise, scatter over the sesame seeds and enjoy!
Step 6 — Kitchen 101
Ensuring the pan is really hot before adding the beef prevents it from stewing and gives it a nice browned finish.