Most of what they serve is not traditional British food, it is high end European cuisine, a lot French inspired & Oliver is into Italian. They are not serving haggis, bubble & squeak, mushy peas, blood pudding and toad in the hole, they're serving top cuts of beef, high end fish, lobsters and so on. It is fancy haute cuisine, not everyday food. It is not what the typical Brit eats for everyday food! I think they just happen to be Brits, but their restaurants here in the USA are not serving traditional British food. We do like some of it, Americans like fish & chips & we probably eat dishes our British ancestors brought with them. I love the UK, but the food is not my favorite part of it.
I will admit I thought mushy peas sounded so gross, but I made them once and I love them. We can not get the authentic kind of peas you use here, but it was still good. We can not get real "bangers" here either.