Follow these step-by-step instructions to create delicious Menchi Katsu:

1. Sauté the Onion: In a small pan, heat 2 tablespoons of vegetable oil over medium heat. Add the finely chopped onion and cook until translucent, about 3-5 minutes. Allow to cool slightly.
2. Mix the Meat Mixture: In a large mixing bowl, combine the ground pork or beef, sautéed onion, egg, panko breadcrumbs, soy sauce, salt, pepper, and Worcestershire sauce. Mix well until all ingredients are evenly incorporated.
3. Form the Patties: Divide the meat mixture into six equal portions and shape them into thick patties.
4. Coat the Patties: Dredge each patty in flour, shaking off the excess. Then coat with additional panko breadcrumbs for a crispy exterior.
5. Heat the Oil: In a deep frying pan, heat vegetable oil to 160-180°C (320-356°F). Ensure there is enough oil to submerge the patties partially.
6. Fry the Patties: Carefully add the patties to the hot oil, frying in batches to avoid overcrowding. Cook for about 4-5 minutes per side until the exterior is golden brown.
7. Drain Excess Oil: Once cooked, remove the patties from the pan and place them onto paper towels to absorb any excess oil.
8. Serve: Serve the Menchi Katsu hot, alongside a bowl of rice and a side of shredded cabbage.