Ever eaten pot roast? That's British food. Ever eaten a roast potato? That's British food. Ever eaten cheese, mushrooms, roast beef or rabbit? Those are all British foods.
British food, properly done (i.e., not the result of WWII rationing or Victorian institutionalisation) is savoury and earthy: roasts, onions, cheeses, mushrooms, potatoes, carrots, turnips. It is hearty and filling, and goes well with the native ale. It's delicious.
Don't knock what you haven't had.
I haven't stayed in a single hotel anywhere that doesn't serve English Breakfast. And I'm sure a lot of people are enjoying a Sunday Roast or a Chicken Tikka Masala every now and again.
But of course, I know there are a lot of ignorant people in the world, which is why I admit the myth persists.
That's not British though, it's Indian.
Chicken tikka masala is chicken tikka, chunks of chicken marinated in spices and yogurt, that is then baked in a tandoor oven
Those don't sound like British words... let's follow the links:
Chicken tikka is a chicken dish originating in South Asia.
A masala is any of the many spice mixes used in Indian cuisine. The name comes from the Hindi word for spice.
The tandoor is used for cooking in Southern, Central and Western Asia.
Did you mean British commonwealth, or British isles?
Nobody is disputing the Asian influence on British cuisine. And nobody is disputing whether or not tikka masala is British.
"...The historians of ethnic food Peter and Colleen Grove discuss various origin-claims of chicken tikka masala, concluding that the dish "was most certainly invented in Britain, probably by a Bangladeshi chef".[14] They suggest that "the shape of things to come may have been a recipe for Shahi Chicken Masala in Mrs Balbir Singh’s Indian Cookery published in 1961".[14]..."