Rinse 400g of blueberries gently under running water to remove impurities. Drain well and pat them completely dry using kitchen paper towels. This step is crucial to ensure the yogurt and chocolate adhere properly.

Place the blueberries in a container and pour in 300g of Greek yogurt. Mix well to ensure each blueberry is fully coated. Use a spatula to form small clusters. Transfer the clusters onto a baking tray lined with parchment paper. Freeze for at least 4 hours or until completely solid.

In a heatproof bowl, combine 150g of chocolate and 50g of coconut oil. Add some water to a saucepan and heat it over low heat. Place the bowl with chocolate and coconut oil over the water. Melt the mixture slowly using the double-boiler method, stirring continuously until smooth and silky.

Remove the frozen yogurt clusters from the freezer. Dip each cluster into the melted chocolate, ensuring they are evenly coated. Place the coated clusters on a tray lined with parchment paper or a cooling rack. Allow the chocolate to set naturally in a cool, well-ventilated area.