I might be late to help. We spent 8 or 9 days in Madrid. Two short stays one at each end of our trip. I must say, go to Rayuelas. Or how ever that other person spelled it. Excellent. Head south from the Palacio Real, past the cathedral, cross the viaduct and turn to your left. It is your first left. It will be the first building on your left as you go down hill. I think the name is on the side of the building facing you as you approach.
Excellent prices, a diverse menu, good service, and wonderful food. We ate there three nights in a row. I'd go back tonight if I were n't in central Wisconsin.
And the toilets are first class. My wife was shocked to find hot water, toilet paper, hand towels, soap, and I forget what else, but all in one place. If she is happy, I am happy.
Beef cheeks in a wine reduction...nice. A couple fish offerings. 10 Really nice racions (large tapas, of which I tried four or five). Tomato and mozarella with balsamic vinegar salad maybe designed to be shared, but I ate it all. Sally had a chicken salad, again, maybe to be shared...she ate it all. An 'Arab' type of chicken wrapped in filo dough. Really, there is something for everyone at this place. Kitchen usually opens at 8:30, 20:30.
Just one step off the tourist path and that is what makes the difference.
Gosh, now I am hungry.