In a small bowl, toss together the bread crumbs and 1 teaspoon of salt. In another small bowl, crack the egg and beat. To a medium sauté pan, set over medium high heat, add three tablespoons of oil. Drop the cubes of tofu, in batches, into the beaten egg first and then transfer them to the panko bread crumbs—make sure all sides of tofu are coated. Doing this in batches, place the tofu cubes in the hot oil and fry until golden brown on all four sides, about 5 minutes per batch. Transfer the tofu to a paper towel to dry. Repeat with the remaining tofu cubes.