For the tzatziki, cut the cucumbers in half. Cut one of the cucumbers into two lengthwise and scoop out the seeds with a teaspoon. Thinly slice. Finely chop the dill.
In a bowl, mix together the cucumber, grated garlic, greek yoghurt, dill, lemon juice and olive oil. Season to taste, cover and set aside.
Prepare the salad. Cut the other cucumber in two lengthwise. Scoop out the seeds with a teaspoon then thinly slice. Halve the cherry tomatoes and peel and thinly slice the red onion.
Place all the veg in a bowl along with the olives, red wine vinegar and olive oil. Give everything a good toss together.
For the burgers, mix the minced lamb, garlic and dried oregano and season generously with sea salt and ground black pepper.
Using your hands form 8 large patties and set aside on a plate.
Place a large frying pan over a high heat and fry for 3 minutes either side or until the burgers are medium and cooked through.
While the burgers are cooking, heat a large griddle pan over a medium high heat. When it has come up to temperature, toast the buns until warmed through and you have char lines.
Slice the halloumi into 16.
To the griddle pan, add the halloumi slices and cook for a minute either side until charred, taking care as they will be very soft.
Assemble the burger with the halloumi, baby gem lettuce, dollops of tzatziki, and the salad served on the side.