Location was tricky to find, but it is very close to the Spitting Llama bookshop on Calle España, between Colombia and Ecuador. Look for the yellow building and enter through the white arch. It shares a lovely courtyard with Ñaupa House Hostel and a number of other businesses (Mocafé is also nice).
When we went, 20bs per person bought us a delicious lunchtime buffet. On metal trays, we helped ourselves to the dozen inventive and tasty salads, and were served one of two vegetable soups plus rice and a choice of potato and gluten meat curry or a gluten meat and vegetable skewer. Condiments of various kinds were available to spice things up. The courtyard is a lovely place to sit and it was popular with other locals. We left full and happy.
The lady on the till was very friendly and didn't mind my bad Spanish. If you order a day in advance, she also sells gluten meat (seitan) to take away for cooking at home. 30bs bought me 500g, which came in a ball for slicing, frying, roasting etc.
Updated from previous review on Thursday June 18, 2015