Place Kabocha in a microwave safe bowl. Cover and cook 6-8 minutes in microwave until soft. Mash Kabocha in the bowl.

Heat oil in a pan and cook ground beef until browned. Discard some excess oil. Add onion and saute until onion is cooked.

Mix Kabocha and meat mixture and add salt, pepper, and nutmeg. Let it cool.

Shape Kabocha mixture into small round pieces (or 8 oval shapes.) Refrigerate for an hour.

Coat with flour, then eggs, and finally Panko (bread crumbs).

Heat deep frying oil to 350-375F, and fry them until golden brown.