For the best texture, drain the tuna very well so the patties hold together and crisp instead of steaming in excess moisture. Chilling the formed patties for a short time before cooking makes them easier to flip, especially if your kitchen is warm or the mixture feels soft. Use a non-stick or well seasoned skillet and moderate heat to avoid burning the cheese while still creating a golden crust. The patties keep well in the refrigerator for up to 3 days and can be reheated in a dry skillet over medium heat until warmed through and re-crisped. To freeze, shape the patties, freeze them in a single layer on a baking sheet, then transfer to a freezer bag and cook from frozen over slightly lower heat, allowing extra time.