In a skillet, combine the broth, wine and lemon. Bring to a boil.

Add the salmon; make sure the fish is covered by the liquid. (If not, add additional equal parts of broth and wine).

Lower the heat and let fish simmer for approximately 10 minutes or until fish just flakes with fork.

In a small bowl, mix together the yogurt, dill, salt and mustard. Set aside.

Using a slotted spoon transfer fish out of poaching liquid and place on plates.

Spoon the dill sauce over each fillet.