Open the coconut milk and scoop the thick coconut cream from the top and set aside (see more details about coconut cream).

Bring the 4 cup of water, beef and peanuts to boil, skimming the scum from the surface for about 5 minutes. Lower heat to medium and continue to cook at a low boil uncovered, for approximately one hour. Remove from the heat and set aside.

Separately, bring the potatoes to boil in enough water to cover for approximately 20 minutes until just slightly under-cooked (al dente). Drain and discard the potato water (or reserve to make your own sourdough mix!). Set the potatoes aside. While the beef is cooking you may make the homemade Massaman Curry Paste.

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 and peanuts in its broth and remainder of coconut milk, fish sauce, palm sugar, tamarind, cinnamon stick, potatoes and onion. Bring to a boil. Reduce heat to low and cook 10 minutes.

Adjust seasoning with fish sauce, palm sugar and tamarind water to taste. Massaman curry should be slightly sweet with a very subtle sour note from the tamarind. Serve with pickled ginger or cucumber relish as condiments.