You can make this dish with any wild or domestic duck or goose, and you can use either skin-on or skinless breast meat. I used skinless breast meat here. If you want to use skin-on, sear the skin side of the duck breast until it's crispy and set aside; don't cook the meat side. Follow the recipe as written from there. Most of the ingredients here are available at any major supermarket, and those that might be hard to find I've listed as optional. But each one adds to the authentic Thai flavor, so try to get them if you can. The curry paste is the most vital: If you can't find it in your market, you can buy red curry paste online.
1tablespoonminced lemongrass(optional, white parts only)
1yellow onion,sliced thinly top to root
2to 6 small hot chiles,chopped
1/4cupThai red curry paste
1 13-ouncecan coconut milk
2tablespoonssugar(palm sugar if you can get it)
1poundduck or goose breasts,sliced thin
Lime juice to taste
1/4cuproughly chopped cilantro
Heat the peanut oil in a wok or a heavy saute pan over high heat. The moment it smokes, add the lemongrass, ginger and garlic and stir-fry for 1 minute. Add the onion and chiles stir-fry another minute or two, then mix in the curry paste. Stir-fry the curry paste until it begins to separate a little, about 2 minutes.
Pour in the coconut milk and stir well to combine. Fill up the coconut milk can with water and pour that in, too. Add the fish sauce and the potatoes and simmer, covered, until the potatoes are almost tender, about 15 to 20 minutes.
When the potatoes are just about tender, add the pineapple chunks and the sugar. Add salt or more fish sauce to taste. Cook the pineapple for a minute or two before adding in the sliced duck breast.
The duck breast will release some juice in a minute or two. When it does, stir the curry well and add the cilantro and lime juice to taste. Turn off the heat and serve immediately over white rice.