Lemon Mascarpone Panna Cotta

Ingredients

• 2 teaspoon (1 small envelope) plain powdered gelatin
• 2 tablespoon cold water
• 1 cup lowfat milk
• 1/2 cup sugar
• 1 1/2 cup plain nonfat greek yogurt
• 1/3 cup mascarpone, creme fraiche or sour cream
• finely grated zest (yellow part only) of 1 small lemon
• juice of 1/2 small lemon
• pinch salt
• lemony rhubarb compote
• sprigs of fresh mint for garnish