To make mini tostadas, using a 3-inch round biscuit cutter, cut 3 rounds out of each tortilla (you should end up with 21 rounds). Warm about 1/2 inch of oil in a large frying pan over medium-high heat. Fry the tortilla rounds until crisp then transfer to a wire rack lined with paper towels and set over a baking sheet to drain. Set aside.

In a bowl, stir together the ahi, ponzu, and sesame oil; cover and refrigerate. In another bowl, stir together the mayo and sambal oelek; cover and refrigerate. In a third bowl, stir together the cabbage and cilantro, then sprinkle with the vinegar and season with salt and pepper.

For each tostada, spread a little of the mayo mixture on the tostada shell. Top with about 1 tbsp of the ahi mixture, then top with the cabbage slaw, and a slice of avocado. Serve with the lime wedges alongside for squeezing. Serve at once.