1) Preheat the oven to 350°F. Spray the baking dish with cooking spray.
2) Wash the salmon steaks and pat dry with a paper towel.
3) In the baking dish, arrange the steaks.
4) Pour wine all over the steaks and sprinkle with 1/2 teaspoon of dried tarragon leaves.
5) Bake for about 15 minutes or until done.
6) In a saucepan, add yoghurt, mustard, 1 teaspoon of tarragon and cook over low flame until the mixture becomes warm. Keep stirring the mixture in between.
7) Divide the tarragon sauce into four equal portions. Pour over each plate.
8) Arrange the salmon steaks over the sauce.
9) Garnish the steaks with lemon slices and chopped parsley.