Cut sweet potatoes into thick slices (3 to 4 cm) and cook. Dice onion, sauté with garlic and butter until translucent. Add all other ingredients except the sweet potatoes and cook a little bit. Then add the sweet potatoes for a few minutes.
I served with leaf salad and Chinese beer.
Notes: paradeis marrow is unnecessary, recipe tastes more Indian. Quite spicy with 1/2 tsp chili spice. Could also taste quite good with butter beet. Finally sprinkle with coriander greens.