Trim top and bottom from squash. Using knife or good quality vegetable peeler, carefully remove rind and scoop out seeds; discarding both. Shred flesh of squash on coarse side of box grater or grater blade on food processor (approx. 4½ cups/1.125 L shredded squash.) Spread shredded squash over clean kitchen towel. Roll towel, with squash enclosed, into a "log". Twist to squeeze out excess moisture; discard liquid.
Transfer squash to large bowl. Mix with green onions, garlic, curry powder, salt and pepper. Stir in egg; sprinkle in flour. Stir until mixture holds its shape when mounded. Scoop into 16 equal portions; form each into 3-in. (8-cm) diameter patties on work surface or platter.
Preheat oven to 425°F (220°C). Meanwhile, heat 1 tbsp (15 mL) oil in large non-stick skillet set over medium heat on stove. Cook patties, in batches, about 2 min. per side, until lightly browned. Add remaining oil to skillet as required. Transfer browned patties to parchment paper-lined baking sheets.
Bake 10 to 12 min., or until tender. Serve rosti with a dollop of yogourt and sprinkling of cilantro or parsley.
Serve leftover rosti for breakfast topped with a poached or fried egg.