General hints'n'tips for Borough Market, seeing as someone asked via PM and it is worth fitting into a London trip.
Upside of Borough Market - lots of quality produce all in one place, plus stalls where you can buy stuff to eat straight away.
Downside - VERY crowded at some times of some days. Normally, I can only get there on Saturday, due to their restricted opening times, and Saturday is when everyone in my situation goes. If you can get there early, it's a good idea.
It is a bit of a labyrinth, so if you spot something and think "I'll take a look at that later", finding it again can involve a bit of wandering around.
There are people who knock Borough Market, especially as it has become more well-known, and some produce can be pricey, but if you take your time, buy a glass of something to sip and tour all the stalls before you start buying,
Then start with the heavy/hard stuff (meat, bottles etc.) and work your way through to the light and fragile (the selection of mushrooms is excellent at the big vegetable stall) and you'll end up poor but happy. Ask to take a look through the freezer at Exotic Meats, as what they have up front is just the burgers.