Add the mashed potatoes, ½ cup bread crumbs, and dill, and mix until well-combined.
Form 8 equal patties from the salmon potato mixture. You can also form 12-16 mini patties, if you want more crispy edges or smaller sized patties as salad toppings.
Optional: dredge each patty in extra breadcrumbs, if you want to make sure they don't stick to the pan while frying, or if you want extra crispy patties. (See notes)
Optional: Fry a test patty to make sure it doesn't stick to the pan. (see notes)
Preheat a large non-stick skillet, and add 1-2 tablespoons olive oil. Carefully place 4 patties down into the hot oil and cook over medium heat for 3-4 minutes on each side, flipping carefully with a silicone spatula to not scratch the pan. Let the patty get golden brown on both sides, but don't let it burn. Set the cooked patties aside on a plate with a paper towel, and add more oil to cook the remaining 4 patties.
Stir the sauce ingredients together in a small bowl and drizzle over the patties to serve.
Mashed potatoes: The mashed potatoes should be well-seasoned for this recipe. I recommend simply using sour cream and chive instant mashed potatoes to make these patties!Breadcrumbs: If your mashed potatoes are not well-seasoned, you might want to use Italian breadcrumbs for this recipe. Otherwise, plain breadcrumbs are just fine!If you start cooking the patties and find that they are sticking to the skillet, you will need to dredge the patties in extra breadcrumbs. This will help them not fall apart in the pan and will make them extra crispy.I recommend frying a "test patty" before you fry all the patties in the next step, to make sure it does not stick. If they do, dredge the other patties in breadcrumbs.If the potato salmon mixture is a little crumbly and falling apart, you can add a tablespoon or two of Dijon mustard or mayo to the mixture.If the potato salmon mixture is too sticky and wet, add a little more breadcrumbs to the mixture and dredge the patties in breadcrumbs.Try adding shredded Parmesan cheese or any other shredded cheese to the patty mixture. What to serve with salmon potato patties: try these over salad, in a pita, in a bun, over rice.