I like chickens feet in black bean sauce (common dim sum dish).
A hotpot is a stock in which you cook various vegs, fish balls (like a meat ball but most often made with white fish instead of the usual mince), sliced meat (thinly slice beef for example) and fish, shellfish, tofu, noodles. Anything you like really. The stock can be flavored and made spicy too.
It's a very communal, shared experience. Perfect for get togethers with family or friends.
My favourite version is a Korean version, where you have stock in the middle with a griddle around the pot to barbecue veg and meats. Super tasty experience.
The restaurants in Chinatown London will often have Chinese menus that include additional items, not sure why those aren't offered to non-Chinese readers. But if you're vaguely familiar with "authentic" Chinese food, I expect you could describe and ask for it specifically.
Takeaways in the UK were generally started by Cantonese Chinese, mainly from HK. But over the decades as 2nd generation children have not followed their parents into the catering trade (often encouraged into more stable white collar professions), a lot of takeaways have been taken over by the next generation of Chinese immigrants who have been from mainland China - so nowadays there's a lot more food from different regions on offer. In Chinatown there has been a noticeable shift from Cantonese to Mandarin, from the restaurant & shop staff as well as the customers.