Medi For All Tips:
Use full-fat or 2% yogurt if that is what you have - nonfat is not required here.
Use any other lettuce-like green that you like instead of watercress.
Serve on whole grain bread instead of pita if you prefer, or serve with whole grain crackers for a snack.
You can substitute 1/2 teaspoon of dried dill instead of fresh, if that is what you have, or if you won't use an entire bunch of fresh dill. Taste and add more dried dill to taste if needed.