Place the dried chiles in a medium bowl and cover with warm water to rehydrate. Let them sit for 30 minutes, or until soft. Drain and save the water.
Place the pumpkin on a large cutting board and, using a large chef’s knife or serrated knife, cut away the skin. Remove the pumpkin seeds and discard (or wash, dry, and bake in the oven with a little salt and cayenne, as a snack). Cut the pumpkin into 1 ½-inch / 4 cm chunks.
In a wide pot, Dutch oven, or deep skillet over medium flame, heat 3 tablespoons olive oil. Add the onions, lower the heat, and cook until the onions are soft and slightly caramelized, about 15 – 20 minutes. Stir the onions occasionally. Stir in the garlic.
Cut the rehydrated chile peppers into thirds across the width.
Add the pumpkin to the pot, and stir to coat in the oil. Add the peppers, mint, paprika, cayenne, salt and pepper.
Cook, covered, over low heat, until the pumpkin is tender but not mushy. Gently stir in the vinegar and adjust seasoning with salt and pepper. Remove and serve.