Preheat the leftover lamb roast and roughly shred the meat with a fork.
Cut the burger buns into halves and toast them.
In a small bowl, mix together the ketchup, chili garlic sauce, mayonnaise and chopped red bell pepper.
Set aside.
Spread the sauce over the bottom of bun.
Arrange the salad leaves evenly on the burger bun.
Top the base of the burgers with shredded meat and sliced onions, tomato slice, cucumber.
Add a tablespoon of prepared sauce to each burger.
Top with the red and green bell pepper slices and cover with other half of the burger.
Cut into halves.
Best Ever Roasted Lamb Burgers are ready to serve.