1. Pre-heat oven to 160°C.
2. Make the pickled red cabbage: In a large bowl, stir together the vinegar, sugar and boiling water until the sugar is dissolved. Add the cabbage and toss until coated. Set aside.
3. Prepare the lamb burger patties: Combine and mix together all of the ingredients in a large bowl. Divide into six equal portions and shape into patties that are around 1cm thick.
4. Heat the BBQ or pan on medium - high heat. Add oil and cook patties without moving until the bottoms have browned, about 1 - 2 minutes. Flip and continue cooking for another 1- 2 minutes, transfer to an oven tray and finish cooking in oven (10 minutes) or until cooked through. Keep warm
5. Meanwhile, make mayonnaise by stirring together all ingredients in a small bowl.
6. Toast the burger buns in the pan or under the grill in the oven.
7. To assemble: Generously spread harissa mayo on the inside of each bun. Place the lettuce, pickled cabbage and feta on the bottom halves of the buns. Top with grilled burgers. Finish with the top halves of the buns and serve
*While Medjool dates are high in natural sugars, they are low on the glycemic index thanks to a balanced amount of soluble fiber. The complex carbohydrates found in Medjool dates are digested at a slower rate, making them a source of dietary fiber and releasing energy to the body over a longer period of time.
