Drain your 2 cans of tuna and add the tuna meat to a large mixing bowl.
In the bowl with the tuna, add in the green pepper, onion powder, garlic powder, salt, egg, mayonnaise, and 1/4 cup of breadcrumbs.
Mix everything together with a fork to break up the larger chunks of tuna.
Once you've made the tuna mixture, sprinkle the remaining 1/4 of breadcrumbs onto a plate.
Take about 1/2 cup of mixture and form it into a patty in your hands. Place the patty on the plate with the breadcrumbs turn over to coat both sides. (If your patties are breaking, just keep it in your hand and sprinkle with the crumbs instead of trying to flip it on the plate)
Heat the oil in the pan over medium heat and cook the patties for about 4-5 minutes per side. (I use 2 thin spatulas to turn them so they don't break. One to get under the patty and the other to slowly catch it as I turn it over).