2 4-oz cansskinless boneless sardines in water, drained
1lbleftover roasted Russet potatoes, skin removed, about 2 potatoes
3-4tablespoonsfinely chopped red onion
Heat about 1/4 inch oil in a large skillet.
Place the sardines, potatoes, mayo, and mustard in a medium bowl and, using a potato masher, mash until smooth. Stir in remaining ingredients. Form into 3-4 inch cakes, using a firm hand to really compress the mixture together.
Fry, turning once, until golden brown. Drain on paper towel-line plates.
Serve warm or at room temperature.
If your mixture is very wet and not sticking together, add in some bread crumbs.