Melt sugar and water together in a saucepan over medium high heat and cook until liquid becomes light golden in color. Stir in walnuts, making sure they are coated evenly and sugar has become a darker golden brown. Remove from heat and transfer walnuts to a piece of parchment paper. Cool completely and chop into bite size pieces.
In small bowl, toss apple slices with 1 tbsp (15 mL) of lemon juice and set aside.
In a small food processor, add avocado, olive oil, 2 tbsp (30 mL) tarragon, remaining lemon juice and water. Puree until smooth.
In a large pot, boil zucchini noodles according to package instructions.
Strain well and divide zucchini noodles between plates. Top with sliced turkey and apple. Sprinkle with walnuts and garnish with tarragon leaves. Serve with dressing.