Peel bananas and cut them into slices. Wash strawberries and cut into quarters. Put the sliced fruit into freezer bags and freeze for at least 6 hours or overnight.

Wash rhubarb and cut into slices. Add rhubarb to a small saucepan together with the lemon juice and a pinch of salt, and cook it for about 15 minutes until the rhubarb is completely broken down. Stir in 1 tbsp stevia and vanilla. Taste and adjust sweetness.  The rhubarb compote should be quite sweet. Once frozen and mixed with the other ingredients, it will taste less sweet! 

Turn off the stove and pour the stewed rhubarb into a separate bowl. Allow it to cool to room temperature, then store it in the fridge for at least 2 h or overnight.

Now add the chilled rhubarb as well as the frozen fruit to the blender and pulse to blend until you have a smooth ice cream. Add more sweetener if desired.

The nice cream should have soft serve texture when it comes out of the blender. For a more scoopable texture, pour the nice cream in an airtight container and put it in the freezer for about 2 hours more. 

Leftovers can be stored in the freezer. Make sure to allow the nice cream to stand at room temperature for about 4 minutes before serving.