Lightly butter the gelatin mold/ramekins or use some water to wet the mold/ramekin and set aside.
Place a small sauce pan over low heat, add milk and stir in sugar, vanilla extract and lemon zest. When the sugar has completely dissolved, turn off heat and set aside.
Heat another sauce pan over medium heat. Add water and stir in Agar Agar powder. Whisk the Agar Agar mixture to prevent it from hardening. Once the mixture starts to simmer, reduce heat to low then whisk continuously for 2 minutes. Turn off heat and add milk mixture to Agar Agar, whisk until well combined.
While the mixture is still warm, transfer to individual gelatin molds/ramekin cups. Once the contents cool down, place plastic wrap and chill in the fridge*.
Unmold* the chilled blancmange and serve with strawberry sauce.