Start in the morning and keeps the peels of two bananas aside. Put them in a bowl with water and add some turmeric (1/4 tablespoon). Let them soak at least 1 hour, but you can leave them there also for the rest of the day.
Peel the onion and cut it into slices.
Chop the ginger into fine pieces.
Halve the red chili pepper and remove the seeds. Then also slice it into fine pieces.
Take the banana peels out of the water. Remove the wooden parts and cut them into fine slices of app. 3 cm long.
Heat the coconut oil in a wok. Then add the onions, ginger and chili pepper. Bake them for a few minutes and then add the spices: red curry paste, the rest of the turmeric powder, the mustard, the cumin powder, some pepper and salt.
Then add the banana slices and the roughly chopped walnuts and bake for a few minutes while constantly stirring.
Pour in the water and let it simmer for 15 minutes, until you have a smooth curry paste. Taste and season with extra salt or pepper if needed.
Serve this delicious curry hot with some basmati rice.
A good advice: don't throw away the water in which you soaked the banana peels. They are a perfect fertilizer for your plants.