I've been having lunch with my friend Beth once a week for over 20 years. One of our favorite places is Good Luck Cafe Deli at 621 Kearny Street, between California and Sacramento. This is a cash-only business run by a very friendly and patient Chinese couple who make sandwiches to order. There are pictures of sandwiches on a large poster in the window, but they will cheerfully make any combination you want. There are a few small tables and some counter space, but their business is mostly takeout, so you can always get a seat if you want to eat there.
Beth and I are pretty much set in our preferences. I always get roast beef and cheese on a whole wheat roll, no mayo and no jalapeno. There is a large selection of bread to choose from, and it's warmed after you order your sandwich. This time I added avocado, which was perfectly ripe but made the sandwich too big to fit in my mouth, so I ate most of the avocado before tackling the sandwich. All this cost me only $8.00.
There is a good selection of chips, snacks, salads and soft drinks to round out your lunch.
Beth's choice is eel on Dutch Crunch, no mustard. With a bag of chips and tax, she paid $8.12.
These are the best deli sandwiches you're going to find. Even though I don't go to the financial district every day any more, sometimes I get on the cable car and get a Good Luck sandwich by myself.