Add 1 cup of coconut milk to a hot wok and bring it to a boil. Add the curry paste, stirring it in well. Let it fry for about 2 or 3 minutes.
When the oils in the curry and coconut are bubbling and separate from the spices, add the beef to the pan and stir into the spices until it is well coated. Fry on all sides until the chunks are well seal and lightly browned.
Add the second cup of coconut milk, stir in well, and let it get hot again.
Add 2 cups of water, stir in well, and let it come to a nice boil. Then add the potatoes, onion, peanuts, cinnamon stick, and bay leaf. Simmer, covered, for about an hour.
Add the sugar and citrus juices. Stir well until the sugar all melts. Next, season to taste by adding small amounts of tamarind pulp until the flavor is a nice balance of sweet and just a little sour.
Remove from the heat and let stand for 15 minutes before serving.