What's the plural of "Full English"?

Full English as in full English breakfast.

Solution 1:

It depends whether you include the word 'breakfast' (often dropped).

Two full English breakfasts please.

Two full English please.

Solution 2:

I suppose it depends on the usage. If one has been asked "What will you be having for breakfast?", it would be appropriate to say "Two full English". It has already been established that you're ordering breakfast, so you're describing what type and how many breakfasts you will be ordering. The noun "breakfast" has been omitted from your reply.

If asked what you're ordering at a steakhouse, you wouldn't reply "two medium rares, one medium". You would reply "two medium rare, one medium". You shouldn't pluralize an adjective just because the noun has been omitted. This can be a bit of a gray area, though, because so many adjectives for various things can also be used as nouns. Some cases are more obvious than others. For example, when ordering martinis, you might ask for "three shaken", but you certainly wouldn't ask for "three shakens", because you simply can't do that with past participles. However, you might order "two reds" from the sommelier, indicating that you would like two glasses of red wine (or perhaps two bottles, if work was especially rough that day). In this case, though, "red" is functioning as a noun. You might also get yourself two different varieties of red wine when ordering like this.

If the menu item is explicitly named "Full English" or "The Full English", then it would be appropriate to say "Two Full Englishes", since it has been turned into a proper noun. But for "full English", I would argue that it is not yet a proper noun unto itself.