Heat the sunflower oil up in a large pan. Fry the onions for 5 minutes and then add seasoning such as oregano and garlic, cooking for one to two minutes.
Stir sugar into the beef mixture, and then pour a little vinegar over it. If you aren’t planning on freezing your burritos, this is when you can add chopped tomatoes to the beef mixture and stir it in.
Once you have heated the tortillas and they are ready to go, begin lining up rice and beef along with each tortilla, making sure to add any toppings you like such as tomatoes, cucumber, or lettuce.