Spray a large frying pan with low calorie cooking spray and place over a medium heat. Sauté the onions and peppers for 5 minutes until softened. Place in a large mixing bowl and allow to cool.
Combine all of the spice mix ingredients together in a small bowl and set aside.
Prepare the blue cheese dressing by lightly mashing the cheese and the yoghurt together with a fork, mixing well, but keeping a chunky texture.
When the peppers and onions are cool, add the mince, panko breadcrumbs and half the spice mix. Add the egg and mix together throughly. At this stage, you can cook a small penny sized piece in a hot frying pan and taste. Adjust the seasoning by adding salt and black pepper to taste. Form the mixture into 6 burgers. Cover and refrigerate for 20 minutes to firm up.
When ready to cook, spray the burgers liberally on both sides with low calorie cooking spray and then rub in the remaining spice mix.
Place the frying pan on a medium to high heat and add the burgers. Cook for 4-5 minutes each side. The spice coating should blacken, but not burn. You may need to do this in 2 batches.
Split the rolls in half and fill with the lettuce, tomato and onion. Place a burger on top and then dollop a spoonful of the blue cheese dressing on top. Enjoy!