To make the chutney, in a small, dry saucepan over medium heat, toast the cumin, garam masala and ginger, shaking the pan occasionally, until fragrant, about 1 minute. Remove from the heat and let cool for about 2 minutes.

Break up the tamarind paste with your fingers and remove any extraneous seeds. Add the tamarind and 2 cups water to the pan and return to medium heat. Simmer the mixture, stirring and mashing the tamarind constantly, until reduced by one-half, about 15 minutes. Taste and adjust the seasonings with salt and sugar. Pour the chutney into a small bowl, let cool, cover and set aside at room temperature.

To make the samosas, preheat an oven to 400°F.

Cut the squash in half lengthwise and scoop out and discard the seeds. Place the halves, cut sides up, on a rimmed baking sheet and drizzle with 1 Tbs. of the olive oil. Bake the squash until tender when pierced with a knife, about 40 minutes. Let cool until easy to handle. Scoop the cooled squash flesh into a bowl and discard the shells.

In a saucepan over medium-low heat, warm the remaining 2 Tbs. olive oil. Add the onion and garlic and sauté until the onion is soft, about 5 minutes. Remove from the heat and stir in the curry powder. Add the squash flesh and mash with a potato masher until almost smooth.

Stir in the salt and sugar, then taste and adjust the seasonings.

In a small bowl, beat the egg with a fork until blended. Lay about 5 wonton wrappers on a work surface; keep the remaining wrappers covered with a slightly damp kitchen towel. Spoon 1 scant Tbs. of the squash filling in the center of each wrapper and flatten with the bottom of the spoon.

Brush the edges of the wrapper with the beaten egg. Fold each wrapper in half on the diagonal, forming a triangle, then press the edges together to seal the filling inside; set aside. Repeat with the remaining wrappers and filling.

Preheat the oven to 200°F. Line a large baking sheet with paper towels and place a wire rack on top. Pour canola oil into a heavy, high-sided skillet to a depth of 3 inches and warm over medium-high heat until very hot. Working in batches, add the samosas to the oil and fry, turning once, until golden brown on both sides, about 2 minutes on each side. Using a slotted spoon, transfer the samosas to the rack to drain and keep warm in the oven.

Cook the remaining samosas in the same way, adding oil to the pan as needed.