Break the salmon up in a bowl. Add the onion, eggs, mustard, dill, pepper and salt. Mix together.
Add the potatoes and combine together.
Heat a couple of tablespoons of oil over medium heat in a skillet.
Take 2/3 cup of the salmon mixture and add to hot oil. Press down to form a patty.
Add three more patties to oil. Cover and cook 3 -5 minutes or until browned.
Gently turn over and cook, covered, another 3 -5 minutes or until crispy.
Remove to a baking dish and keep warm in a 200 degree oven.
Add more oil if needed and cook the rest of the patties.
While the last of the patties are cooking, combine the sour cream, dill and lemon juice together.
Serve patties with the dill sauce.