Preheat the oven to 200C, fan-forced. Thinly slice the onion. Cut the cucumber into 5cm-long batons. Shred the carrot using a julienne peeler or coarsely grate with a box grater.
Step 2 — Pickle carrot
Combine 2 tsp white vinegar, ½ tsp sugar and a pinch of salt in a bowl. Add the carrot and toss to combine. Set aside to pickle, tossing occasionally, until needed.
Step 3 — Warm tortillas
Enclose the tortillas in foil. Put in the oven for 8 mins or until softened and warmed through. Meanwhile, heat 2 tsp vegetable oil in a medium frypan over medium heat. Cook the onion, stirring, for 3-4 mins until softened.
Step 4 — Brown beef
Increase the heat to high. Add the beef mince to the onion and cook, breaking up the lumps with a spoon, for 3-4 mins until browned. Reduce the heat to low, stir in the hoisin sauce and season with pepper. Cook, stirring, for 2-3 mins until combined. Remove the pan from the heat.
Step 5 — Serve up
Spread the tortillas (see Make it yours) with the mayonnaise, then top with the beef mixture, pickled carrot and cucumber. Roll up and enjoy!
Step 6 — Make it yours
For an easy hands-on dinner, put the tortillas, mayo, beef, carrot and cucumber in separate bowls on the table and let everyone make their own wraps.