Lemon Curd in Meringue Cups

Ingredients

• 3 egg whites
• 1/2 tsp (2 mL) white vinegar
• 1/4 tsp (1 mL) vanilla extract
• 1/8 tsp (0.5 mL) salt
• 1 cup (250 mL) granulated sugar
• 1/3 cup (75 mL) cornstarch
• 1 1/2 cups (375 mL) cold water
• 3 egg yolks
• 1 tbsp (15 mL) finely grated lemon zest
• 6 tbsp (90 mL) lemon juice
• 2 tbsp (25 mL) butter
• 1 cup (250 mL) blueberries or raspberries