I'm curious if it's totally acceptable in London to pop into a restaurant only to order dessert. I tried doing this in Paris recently and I was not allowed to without ordering an appetizer and entree first.
It depends on the restaurant. I doubt a "fancy" place will let you do that. But there are plenty of pastry shops throughout the city.
I’ve never seen anyone do this.
I did recently read about this dessert only place:
https://cakesandbubbles.co.uk
Not common but I couldn’t say it would never be allowed. It would be ok in most pubs. You can go to a pub and not buy any food at all. Anywhere popular will not be keen on you taking up a table for such a small spend. Maybe if it wasn’t a busy time it may be ok but I don’t think that they will be overjoyed by the request.
For reference, I have written down Hawksmoor (a chain) for their sticky toffee pudding. I do think I saw an image on Google showing a receipt with just the pudding on it.
Here in the states it is not uncommon to go out for dessert and coffee after the theatre or ballet, I wonder if that's true in London.
Caffe Concerto Haymarket. We stopped here post theater for excellent dessert and coffee. Multiple locations across London. A more casual place, or cafe, might be more welcoming.
Instead of going to Hawksmoor ( which isn’t cheap) why not have sticky toffee pudding at Mother Mash on Ganton Street. From there check out Liberty. Not something you’ll find in Pico Rivera….or anywhere in California or the United States. A different shopping experience.
You might find they have the same rule as the restaurant in Paris you referenced. You must make a reservation to eat at Hawksmoor, and that would be a good time to tell them you'll only be ordering dessert.
Why not send them an email and ask whether or not they mind a customer just ordering dessert?
It would be regarded as pretty weird to go to a full service restaurant like Hawksmoor and just have pudding. But at cafes like Cafe Concerto and coffee shops (both chain and independent) it would be fine, although that’s more likely to be cakes. There are a number of dessert places targeting the South Asian market that wants to avoid pubs as well that would work.