If you're not, let me explain: the Chelsea bun is not a million miles from a cinnamon bun - it's dough, rolled up with a cinnamony and a fruity filling, then glazed.
I guess the main difference between the two is that there's a more bread-like cast to the Chelsea bun, rather than a cakey one. Chelsea buns are made with white bread flour and there's no sugar in the dough - all the sweetness comes from the brown sugar in the middle, and the glaze on top.
Here's the recipe I used, only I omitted the egg and used vegan spread rather than butter.
Oh, and I also made it with wholemeal flour because I'm really healthy like that (not in any way at all because that's all I had and I couldn't be bothered to go to the shops. Not at all.) It may not be a traditional Chelsea bun and royalty would probably grumble, but when they stop taking my taxes, then maybe I'll consider doing Chelsea buns right. Yeah, in your face, queen!
The filling of Chelsea buns is often mixed peel or raisins, but I've used a bit of peel and some sultanas because I find raisins creepy. There, I've said it - they freak me out. It's sultanas or nothing here, but if you're making Chelsea buns, you're free to use the dried grape of your choice - I won't tell on you.
They're not that hard to make, and not too much bother if you ignore the rising time of the dough. It's just a case of making the dough, leaving alone for a bit, rolling it out, filling it up and baking. Oh yeah, and glazing it.
I've not made it sound simple have I? Don't let me put you off. Your cup of tea will thank you.