Although there aren't many street food vendors out on a Sunday, there are plenty of good places to eat and drink in the area (we popped into Honest Burgers, a review will be up shortly!), as well as tempting crêpe stands and the ever popular Hummingbird Bakery.
If you're visiting London or are in the area (particularly on a sunny day, as with all places), it's a must-see spot and great for street photography.