Where did Sherlock Holmes get a sandwich?

 There's a pair of lines in "The Red-headed League" that came up during a discussion this week that are just going to keep me wondering:

"There is Mortimer's, the tobacconist, the little newspaper shop, the Coburg branch of the City and Suburban Bank, the Vegetarian Restaurant, and McFarlane's carriage-building depot. And now, Doctor, we've done our work, so it's time we had some play. A sandwich and a cup of coffee, and then off to violin-land . . ."

So, the Vegetarian Restaurant was right there -- would that be where Holmes took Watson for that sandwich and coffee?

We know that the Baker Street rooms were a regular source of sandwiches for Holmes -- Mrs. Hudson seemed to keep some beef and bread on the sideboard for just that purpose. Sherlock Holmes makes one for his pocket on his way out the door in "Beryl Coronet," and Watson refers to him "devouring sandwiches at irregular hours" during "Second Stain" as he ran in and out.

When he's further away from Baker Street, as he was in "Naval Treaty," he gets sandwiches from the little village inn in Ripley to keep in his pocket (as well as filling his flask). His famous cloak must have had some nice, large pockets for sandwich-toting, a feature I rather admire.

Early on, in A Study in Scarlet, Holmes tells Watson that he depends upon his skills at observation and deduction "for my bread and cheese." While not strictly vegan, a sandwich with bread and cheese and some cucumbers or pickles, might have passed for "vegetarian" in the early 1880s? I'm not expert in historic vegetarianism, but it seems possible.

So I just have to wonder if that Vegetarian Restaurant (note the capital letters, which makes it seem like that was its name and not just a description) put Holmes in mind of getting a bite to eat and patronizing Jabez Wilson's neighborhood eatery. And what was on that sandwich!