I've only just discovered this fantastic little salad bar-come-florist right round corner from my studio. It serves freshly made salads that are not only delicious but cheap too! Either take away, or grab the one and only table and eat in.
SOAS university has a small gallery space dedicated to exhibitions about Asia, Africa and the Middle East. There's a small but beautiful Japanese zen garden on the rooftop (currently closed for refurbishment)