This is a non-spicy recipe, since I'm a wimp. If you aren't one, add some Sriracha (or something similar) at the same time you add the potatoes and coconut milk, or, if you have a normal people/wimp mix, just serve it at the table.
1/4 cup peanut (or vegetable) oil
1/2 cup Massaman curry paste (there are a lot of curry pastes, and they probably all taste good, but I use this and I really like it)
2 Tbs fresh minced ginger
1 Tbs fresh minced garlic
1 chopped onion (optional)
2-1/2 pounds chicken breast - cubed
1/4 cup brown sugar
1/4 cup fish sauce
1/3 cup tamarind paste
1/3 cup peanut butter
6 cups cubed potatoes
2 (13.5 oz) cans coconut milk
1/3 cup fresh lime juice (about 2 limes worth)
1/2 cup unsalted peanuts, coarsely chopped
Heat oil over medium heat in a pot big enough to hold everything. Stir in curry paste and minced ginger - cook and stir for 5 minutes or so. Stir in the chicken, and cook, stirring the pieces around for about 8 - 10 minutes until they start to turn white.
Stir in brown sugar, fish sauce, tamarind paste, peanut butter, potatoes, and coconut milk. Bring to a boil, then reduce heat as low as it will go, cover, and simmer for at least 30 minutes - the longer the better. I frequently start this at night and leave it in either a very low oven (~220 degrees) or dump it into the crockpot overnight. There's an additional advantage to this - I don't have to try to find/create refrigerator space. Add the lime juice and cook for an additional 5 minutes before serving.
I think this is usually served with white rice, although I use brown rice for everything: you can also just eat it as is. Serve with chopped (or unchopped) peanuts and hot sauce. It's better the next day.