We invented one of the world's most popular cheese, Cheddar, which is actually named after an English village. Also our national dish is Chicken Tikka Masala. I dare you to say we don't use spices. We invented several varieties of spiced sausage, spiced cakes and fruit bread, even some kinds of spices rum.
Don't get me wrong, lots of British cuisine is lackluster for sure, and I don't think we can compete with the likes of Thailand or Italy. That doesn't apply to everything we do though, and some of our deserts and cheeses are top tier. Thailand is literally known for diplomacy through food as well, so hardly a fair comparison.