Look for anything that says "Asado" -Roasted or "A la plancha" -Grilled, and you may want to ask them too avoid putting much oil if it's "a la plancha".
Avoid the Tortilla de Patata as it's fried potatoes with egg and Croquetas as they are fried and have quite a bit of flour in them.
Becareful with the Sangria too But enjoy!