- Beat the ricotta cheese until smooth. Stir in low fat yogurt, sweetener and lemon rind.
- Pour 2 tbsp of lemon juice in a small bowl and sprinkle gelatin over it.
- Place this bowl over a pan of hot water and stir to dissolve the gelatin completely.
- Quickly stir the gelatin into cheese and mix it evenly.
- Beat egg whites until they from soft peaks. Quickly fold them into the cheese mixture.
- Spoon the mixture into six lightly oiled, individual heart-shaped molds chill them until set.
- Put strawberries and a tbsp of lemon juice in a blender and process until smooth.
- Pour sauce on to serving plates and place the turned out hearts on top.
- Decorate with slice of strawberry and serve!