Tijuana's seafood cart vendors compete so fiercely over their tostada toppings that some stands are known for a single specialty, like octopus or sea urchin, rather than a full seafood menu.
A crisp fried tortilla is piled high with a choice of shrimp, octopus, or ceviche mixed with avocado, tomato, and a squeeze of lime and hot sauce. Street carts throughout Tijuana and Ensenada sell them as an open-faced, fork-required snack.