We recommend using wild caught salmon, and Dijon mustard without any sweeteners in the ingredients. Cutting the raw salmon into chunks and blitzing in a food processor works too if finely mincing isn’t desired.
If you need to omit the egg white, this is a binder in this recipe. You could simply omit this and bake these in a muffin tin instead of using a frying pan and placing them on an open baking sheet.