It's secret except for all the signs in the front. There is a grill in the back and they make really solid tacos. I've had chorizo, longaniza & cecina. The longaniza is spicier. I hadn't had cecina before - it's chopped up salt beef. It makes the taco slightly drier but the salsa helps with that (specify red or green, green is hotter). And it's really good. These guys also bake their own sweet breads and pastries. Coney Island Ave & Beverly rd, Ditmas Park. It's located two storefronts behind Madina restaurant, on Beverly.
Three chorizo tacos $6.75. Walk five minutes and eat them on the benches along Ocean Parkway.