There's nothing quite like a burger and just sometimes there is nothing better than a big fat juicy burger to satisfy the cravings. The sort that is messy, and I mean the whole messy juice down your chin type messy! If you are going to have one, have a proper one. This recipe has a traditional sesame seed bun, but that's where we leave tradition at. My thinking here was a pub grub style dinner in a form of a burger. So inside our bun we have a fat 100% lean steak burger with no fancy ingredients other than lashings of fresh cracked pepper, sweet fried onions, crumbed and baked portobello mushroom, cheese slices and cream cheese mixed with garlic.