http://www.templeofthai.com/recipes/massaman_curry.php
(NOTE: we don't have tamarind water, so replace this with a lime juice/brown sugar mix)

1) Open the coconut milk and scoop the thick coconut cream from the top and set aside.

2) Bring water to a boil, slice beef into thin strips and boil for 5 minutes, skimming the scum from the surface (This is the fat. Remove it. It's disgusting). Lower heat to medium and continue to cook at a low boil uncovered, until fully cooked. Remove from the heat and set aside.

3) Separately, puncture the potatoes, microwave for 2 mins on one side, 1 min on the other side. Then cut into 1 inch cubes. Set the potatoes aside.

4) Cut the onion into small pieces.

5) Make the homemade Massaman Curry Paste.

6) Heat oil in a large wok (or other large heavy bottom pan) over medium heat, add the curry paste and cook briefly until fragrant. Add the reserved coconut cream and fry until it begins to separate, stirring constantly. Add the boiled beef in its broth and remainder of coconut milk, fish sauce, brown sugar, tamarind, cardamom pods (cracked and dry roasted), cinnamon stick (dry roasted), potatoes and onion. Bring to a boil. Reduce heat to low and cook 10 minutes.

7) Adjust seasoning with fish sauce, brown sugar and tamarind water to taste. Massaman curry should be slightly sweet with a very subtle sour note from the tamarind.