The Unagi-yasan Unageya, a rustic downtown unagi-yasan, have usually on the menu 'unagi bones fry, and simmered'(confirm on reservation to reserve some). And, there is a choice of three unadon at 1900.-yens, 'wafu(unagi, nori, green onions)' my favorite, 'kansai fu(kansai style), 'shiro yaki(pure roast)'. Reservation is necessary, even at lunch, and ask to be seated in the first floor, the second floor you will have to sear cross legs.
Here the link if you are interested :
Photo of two of the donburi unadon