My favorite cafeteria in Madrid. The food is always delicious and the dishes are original and tasty. The coffee is one of the best I've had in the city.
They almost always have space despite being a small place. I recommend going early in the morning if you don't want to wait (10-15 min).
They have gluten-free bread and many sweets available. Many dishes can be adapted for celiacs and others are directly gluten-free, such as pancakes with bacon, blueberry jam and mascarpone (highly recommended!).