Begin by pressing the firm or extra-firm tofu to remove excess moisture, then slice into thick slabs.

Set up a breading station with flour, beaten egg (or flax egg), and panko breadcrumbs. Dredge tofu slices in flour, dip in egg, and coat with breadcrumbs.

In a skillet, heat about 1/4 inch of vegetable oil over medium heat until it shimmers. Check if ready by dropping in a small piece of bread.

Carefully fry the breaded tofu slices for about 3-4 minutes on each side until golden brown and crispy. Transfer to a paper towel-lined plate.

Prepare tonkatsu sauce if using homemade by mixing ketchup, soy sauce, mirin, and sugar to taste.

Serve the crispy tofu katsu drizzled with tonkatsu sauce and paired with steamed rice or salad.