British food is a bit like the English language. We robbed everyone else of all the best bits which could get our hands on. We then reimagined them. "Chinese" and "Indian" food are good examples of this.
For proper good English food, you have to go back a bit. It tended to be simple, high quality food, done well. The traditional roast is a good example. Along with its fancy cousin, the beef wellington. A good stew, or casserole can be amazing, when done well. A lot of "rich people" food gets thrown in with "french cuisine".
Beyond those you have the traditional dishes, things like a ploughman's lunch, or a shepherds/cottage pie. Suet pies can be wonderful if done right, and desserts like carrot cake can be excellent. Even the classic British fried breakfast can be a thing of beauty, with proper care.
Unfortunately, almost all of these have been heavily bastardised now. The big supermarkets have conditioned us to crap food. Even finding good ingredients is a challenge now. The fruit and veg we get are dire, and it's difficult to build a mighty tower on poor foundations.
Oh, and also remember, we exported a LOT of our food around the world. British cuisine formed a baseline for measuring other cultures to be measured against.
A lot of "rich people" food gets thrown in with "french cuisine".
A lot of British "rich people" food is french cuisine. What with your nobles being basically french for some time, and also having a boner for our rich fucks' ways for a long time after that
The whole situation is fairly incestuous (a bit like the old money rich). If an English 'french' cook improved something, it would get rolled into 'french' cooking. It could even flow back to the 'french' cooks in France, given time. At this point we just don't know anymore how information flowed.
On top of that, anything that seems to match the French style gets thrown in with French cuisine. Whether it was actually a French invention or not doesn't matter.