Combine the turkey, breadcrumbs, eggs, parsley and spices and mix well.
Form patties with wet hands (this prevents the burger mix sticking to your hands).
Heat a skillet, pan or griddle over high heat. Add the burgers and cook for 4-5 minutes per side until cooked through. Add cheese, if using, and allow to melt.
Allow the burgers to rest for a few minutes. Toast the buns in the same pan until golden.
To make the mayo, combine the ingredients and season to taste.
To assemble the burgers, add a generous dollop of mayo to the bottom buns. Top with lettuce, cooked burgers and toppings of your choice. Add the top bun and serve.