Speedy's Cafe is a small sandwich bar and cafe which is situated in Baker Street just to the right of the door to 221B and 221C.The place is owned by Mr Chatterjee.
The café serves as a convenient meeting place on at least one occasion; Mycroft Holmes sat here with John Watson to discuss Irene Adler, and how they would explain her death to Sherlock.
Mrs Hudson goes there often enough to become friendly with Mr. Chatterjee. She has an argument with him after Sherlock reveals that the boyfriend has a wife in another part of the country