For the chocolate banana with foam, first cut the bananas in half lengthwise and then carefully peel off the skin.
Melt the chocolate coating over a water bath. Apply to the half banana peels and let dry (place in the freezer for a few minutes). Then carefully peel the chocolate from the peel. This will make the chocolate shell for the chocolate banana. To make it thicker, you can coat it again with a little chocolate coating.
Puree the remaining ingredients including 300 g of the peeled bananas and pass through a sieve. Measure 500 g and pour into a siphon bottle. Foam with 2 cartridges.
Squirt the banana foam into the chocolate shell and serve the chocolate banana with foam immediately.