Mix the mince, breadcrumbs, egg yolk, herbs (if used) and worcestershire sauce (if used) together in a bowl with a little seasoning. Divide into two then shape each piece into a flat burger shape.
Heat a non stick frying pan, brush the burgers on both sides with the oil then fry them over a low heat for 10-15 minutes, turning once until the burgers are brown on the outside and completely cooked through.
Split, then lightly toast the inside of the buns then fill with the burgers, lettuce and tomato. Serve with tomato salsa.