A great place to start the day if you are in South London is Federation Coffee in Brixton Village. The food is great and so is the coffee. This is a very chilled place where you can get both and indoor and outdoor experience (even though the whole place is under the Village roof).
Silo is UK's first zero-waste restaurant where everything has been designed with sustainability in mind.
Silo's approach is woven throughout the restaurant and its supply chain; from trading directly with farmers to composting any leftover scraps into compost.