A clean yogurt base under set jelly and fresh fruit.
Mix the jelly powder with the boiling water until dissolved, then stir in the cold water.
Add the diced strawberries and watermelon and chill for 15–20 minutes until slightly thickened but not fully set.
Spoon the yogurt into 6 clear cups to make a smooth base layer.
Gently spoon the fruit-filled jelly over the yogurt in each cup.
Refrigerate for 2–3 hours until the jelly is fully set, then serve cold.