To make Lemon-mint syrup:
Make syrup by mixing sugar with 1/2 cup lemon juice in a small saucepan. Bring to a boil over medium-high. Stir in mint and peel of one lemon and remove from heat. Cover and let steep for 1 hour. Strain.
To make Lemon-mint fruit dip:
Combine 1/2 cup Greek yogurt with 3 tbsp Lemon-Mint Syrup and 1/2 tsp lemon zest. Mix thoroughly. Serve as a dip for fresh fruit.