Teppanyaki at the Japan pavillion at Epcot will do nicely, and if you don't mind a walk or a boat ride, there is also Kimonos at the Swan. Both have excellent sushi and sashimi, and well and a nice variety of cooked foods. Actually, the Swan has historically been the hotel that most Japanese tourists choose, so I expect they keep Kimonos to a higher standard (providing Japanese comfort food, as it were). we have generally preferred Kimonos for this reason, tho as I said, both have very high standards and IMO are a good value for money spent.
Enjoy!