To cook the pumpkin, cut the squash into wedges about 1 inch thick. In a saucepan, heat the oil and add garlic, ginger, turmeric, and salt. Add the pumpkin wedges and enough water to cover. Boil and then simmer until the pumpkin is almost tender. Let cool in the cooking water.
To make the pork stew, cut the pork into pieces and mix with salt and turmeric. Cook onions, ginger, garlic, and chiles in oil. Add the marinated pork and pumpkin cooking water. Simmer until meat is tender. Stir in curry powder, fish sauce, and pumpkin. Simmer until stew thickens.
Let the stew sit for 20 minutes before serving. Bring to a simmer, taste, and add more salt or fish sauce if desired. Serve with mint, cilantro, and lime wedges.
