Kale Moa (Pronounced KAH-lay MOH-ah) is absolutely wonderful. It's full of flavor, and has the best balance of sweet, savory, and spicy. One of my favorite Samoan dishes. Just a note: I personally prefer to use yellow curry as it's mild but still has the curry flavor I love. You are more than welcome to adjust the heat of your curry to whatever you prefer. :)
In a large pot, preferably a stock pot, over medium heat, add your oil and onion. Saute the onion until it is almost translucent.
Add in the garlic, ginger, and curry powder. Saute everything in the pot until these become aromatic.
Add in chicken pieces, 2 cups of water, and 2 cups of coconut milk. (If you're using canned coconut milk, be sure to also use the thick cream on top for a nice, rich, and thick sauce for your kale.) Bring the pot to a boil, then turn heat down to low simmer, and cover. Simmer about 20 minutes.
Add in vegetables, stir. Bring the kale up to a boil once more, then back down to a low simmer, covered. Simmer for about another 20 or so minutes until carrots or potatoes are fork-tender but not falling apart.
Mix together the remaining 6 Tbsp of water with 6 Tbsp of flour to make a quick slurry. (At the point, if you think it could use more heat, feel free to add more curry powder.) Add this to the pot, turning the heat back up to medium, and stirring until thickened. Season well with salt and pepper. Serve with rice.