Put the jelly in a measuring jug and pour in 570ml boiling water. Stir to dissolve the jelly and then let cool slightly.
Place the chopped strawberries in the bottom of 4 x 250ml glasses, reserving a few pieces to garnish.
Pour the jelly into the glasses, then chill for about 2 hours until set. Top with a layer of yogurt and a few of the reserved strawberry pieces to serve.