For Blueberry Sauce:

1. Place the blueberries, water and sugar into a small sauce pan and bring to a boil. Stir until the sugar has dissolved.
2. Pour into a mini food processor and pulse until smooth.
3. Pour through and press through a fine mesh strainer to remove any pith or seeds.
4. Divide the blueberry sauce into serving dishes and place in the fridge to cool.

For the Lemon Mousse:

1. In a small dish, pour the 3 Tablespoons of water. Sprinkle the gelatin over the top and set aside so it will bloom.
2. In a bowl, whisk together yogurt, cream, lemon juice, lemon zest, and vanilla.
3. In a separate metal or heat proof bowl, set over a sauce pan with a small amount of boiling water in it – create a mock double boiler. In the faux-double boiler whisk together the egg whites, sugar and cream of tartar.
4. While constantly whisking bring the egg mixture to 160 degrees. The egg whites will expand and become bubbly. Pour the gelatin mixture into the egg whites.
5. Immediately pour the egg whites into a stand mixer outfitted with a whisk attachment and turn on medium-high. Let the eggs beat until they form stiff peaks – about 5-7 minutes.
6. While running, pour in the yogurt/cream mixture and beat an additional 1 minutes. Pour the whole mixture into the serving dishes over the top of the blueberry sauce.
7. Place in fridge and allow to set for 6-8 hours or over night. Sprinkle with additional lemon zest before serving.