4 cups drained low-fat yoghurt or low-fat Greek-style yoghurt
Combine the blueberries, lime juice, sugar and balsamic vinegar in a saucepan, and bring to a boil.
Cook for 5-10 minutes until the liquid is reduced, and the blueberries have cooked down to a jam-like consistency.
Let it cool. You should have about 2 cups of a thick jam-like sauce.
Spoon 1/4 cup thick yoghurt into the bottom of tumblers or parfait glasses.
Top with a couple of tablespoons of the blueberry sauce. Make another 1/4 cup layer of yoghurt on top of the blueberry sauce, and finish with another 2 tablespoon-layer of blueberry sauce. Cover tightly and chill for at least 1 hour or so.