This panko-crusted causa base was the result of playing around in the kitchen. I loved how the super-crunchy fried panko contrasted with the causa toppings, and since frying makes the potatoes warm, the base works well with entirely different toppings. Sushi-style seafood, yes, but also leftover shredded meat and sauce from any of the beef, lamb, pork, or duck estofados (stews, page 151), or whatever leftover pot roast–style dish you have in the refrigerator.
To keep the potatoes from falling apart as they fry, make sure the causa base is well chilled, and slice the potato base into 1-inch squares or slightly larger pieces. For a quick version, instead of using cut-out causas, tear off little balls of the causa base, flatten them slightly, roll them in the breading, and fry up the tiny causa cakes. The fried causa bases really are best hot, so serve them right away. Keep them in the back of your mind whenever you make the causa base. Like leftover mashed potatoes, you can fry them up for a quick dinner later in the week.
1 Line a baking sheet with two or three paper towels. In a medium, deep saucepan, heat 1½ to 2 inches of oil over medium-high heat until it registers 350°F on a deep-fry thermometer, or fill a deep fryer with the recommended amount of oil and set the temperature to 350°F. Use a frying thermometer or test the oil temperature, or just toss in a little panko; it should bubble fairly vigorously (if the oil smokes, reduce the heat).
2 Place the flour, beaten egg, and panko in three separate small bowls. Use one hand to dip a causa square first in flour, use the other hand to dip the causa into the egg, then use the “floured” hand to roll the square all over in the panko (a handy way to keep only one hand wet and covered in egg). Repeat with the remaining causa squares.
3 When the oil is hot, deep-fry the causa bases in two or three batches until the panko is golden brown, about 2 minutes. Gently flip the causas with tongs halfway through so they brown evenly on all sides. Use a slotted spoon to transfer the causas to the paper towel–lined baking sheet, being careful not to break the pieces. Top the causas and serve them warm, with room temperature or warm toppings.
Makes 12 crispy causa bases