. My favorite is Shepard pie, I know its Irish,
It's English. In England it's called Cottage Pie ; in Ireland it's known as Shepherd's Pie, but it's an English dish :) It's usually made with lamb but in Ireland it's quite often made with beef. If you want to be strictly accurate about it, it's only a shepherd's pie if it's made with lamb and it's cottage pie when it's made with beef but like I say, in Ireland we call it shepherd's pie regardless of the meat used. Nonetheless it's an English recipe.
As far as traditional British versus Polish food goes, I would say there is more variety in British, both in the ingredients and methods of cooking. A lot of Polish dishes taste very similar to each other in my opinion.