I make the pantry version because it's quicker.
1 pouch instant mashed potatoes (there's a variety of flavors, pick any one you like)
Canned tuna (I use 4 small ones because that's usually what's in my pantry. You could get a big can, I guess)
1 egg
Bread crumbs
Crushed garlic
Parsley (FRESH parsley changes the flavor of these things tremendously, but I don't have any. =( )
White pepper
Olive oil
Preheat oven, 400F.
Make the mashed potatoes following the directions on the package. Mix in the garlic (as much as you want), bread crumbs, parsley, and white pepper. Set aside to cool a bit while you drain the tuna.
Add the tuna BEFORE adding the egg, because those potatoes retain heat well and you don't want scrambled egg in your mix.
Make patties in whatever shape or size you desire, brush some olive oil on both sides, and set on a cookie sheet. Top rack, 400F for about 15 minutes (they'll start looking a bit dry), then flip them, turn oven down to 375F, and give them another 15-20 minutes.
This would make about 12 decent patties, but I skimped a bit and they ended up being 13, so I didn't have room for that last one on the cookie sheet. I made it in the toaster oven and it came out crispier and more golden than the others (which I kinda liked better, personally).You can eat these in sandwiches if you'd like. I prefer them over lime juice-sprinkled iceberg lettuce. They taste like summer to me and my 9-year-old loves them.
(I also put some grated ginger in them to appease my ginger fixation. The child did not notice and I didn't feel the need to fill her in)

