In a pan put 500ml of milk, turn on the heat at medium temperature. Once it starts to boil, turn off the heat.
Transfer to a bowl or dish and add another 500ml of milk at room temperature.
Add about 100g of natural yogurt and mix very well.
Cover the bowl with a lid or with plastic wrap.
Take it to the oven with the oven heat turned off and place a glass or bowl filled with very hot water next to it, or simply leave it in a very warm place.
Leave for 12 hours, this time is needed.
Then, after this indicated time, leave in the fridge for 4 hours.
Pour all this cream into a blender and add a packet of strawberry juice powder or 300g of strawberries (the fruit).
Blend it all together very well until combined.
Transfer to a container with a lid, store in the fridge and serve.