Heat a large frying pan over a medium-high heat for 1-2 minutes. Whilst the pan is heating up, brush the chicken breasts with the olive oil and season well.
Reduce the heat a little and pan-fry the breasts for 15-17 minutes, turning occasionally until they are golden. Cut into a thick chunk and check that it is cooked through, with no pink showing. As the breasts cook, create the barbecue sauce by heating the sunflower oil in a medium sauce pan over a medium heat.
Fry the garlic for a minute, stirring constantly, then add the sugar, soy sauce and tomato ketchup. Mix well, bring to the boil then simmer for 5 minutes. Remove from the heat and set to one side.
When the chicken breasts are cooked; remove from the pan and allow to rest for a few minutes before shredding into a mixing bowl using two forks. Marinade in the barbecue sauce, making sure you reserve some of the sauce to serve in a small serving pot alongside the sandwiches.
Create the sandwiches by spooning the marinaded chicken onto the bottom half of the rolls. Top with a lettuce leaf and then the top half of the rolls to create sandwiches. Serve alongside a pot of the barbecue sauce.
For top tips on protecting you and your family when preparing raw meat and poultry, visit Food Safety in the Home and view the full Food safety at home video.