Having come down specifically to sniff this out, we poked our noses under the white awning. “Aha, people. Come in, come in,” chirped a bearded chap. He was Londoner John Quilter, an ex-chef and self-labelled “food busker” — the only one in London, I believe — who each weekend brings with him a pile of fresh ingredients, cooks whatever he feels like on the day and asks you to cough up if you like what you eat.