Bring a large pot of water to a boil over high heat.
To prepare the dumpling filling, combine the pumpkin puree, Japanese curry base, green onions, garlic, coriander leaves, soy sauce, and panko breadcrumbs in a food processor. Pulse a few times, then process until well blended.
Place two wonton wrappers on your work surface, keeping the remaining wrappers covered with a damp towel. Spoon 1 tablespoon (15 ml / 0.5 fl oz) of the pumpkin mixture in the center of each wrapper.
Dip a fingertip in the potato starch mixture and wet the edges of the wonton wrapper. Pull the edges of the wrapper around the mixture and pinch closed.
Fold the dumpling so the ends meet and crimp to close.
Repeat with the remaining wrappers and filling.
Gently drop the dumplings into the boiling water and then turn off the heat.
Stir with a spoon to prevent them from sticking to the bottom.
Let the dumplings cook for 3 minutes.
Remove the cooked dumplings from the pot with a slotted spoon.
To assemble the soup, place ½ teaspoon pumpkin seed oil and ½ teaspoon pumpkin seeds in each of the 6 soup bowls.
Divide the tofu and 3 warm dumplings evenly among the bowls.
Ladle 1 cup / 250 ml of hot dashi into each bowl.
Sprinkle with green onions, if desired, and serve immediately.
Keep unused wonton wrappers covered with a damp towel while you work to prevent them from drying out and cracking.
Do not overfill the dumplings. About 1 tablespoon (15 ml / 0.5 fl oz) of filling is the perfect amount to ensure they seal properly and don't burst while cooking.