In large pot of boiling salted water, blanch parsley until soft, about 2 minutes. Remove with tongs and drain; let cool (do not squeeze dry). Add unpeeled potatoes to pot; boil until tender when pierced with fork, about 45 minutes. Drain and peel while hot. Press through ricer or force through fine sieve. Place on floured work surface and sprinkle with salt; let cool.

Meanwhile, remove large stems from parsley and discard. Mince parsley as finely as possible.

Make well in centre of potatoes; add parsley and 3/4 cup/175 mL of the flour. Using hands and pastry scraper, lightly knead mixture until dough forms, adding more flour if dough is too sticky or too soft (be careful not to overwork dough).

Divide dough into 6 equal parts. Using floured hands, lightly roll each into approximately 18-inch/45 cm long roll, flouring surface as necessary. With pastry scraper or sharp knife, cut rolls into 3/4-inch/2 cm pillow-shaped pieces; place on lightly floured baking sheets, leaving space in between each. (Make-ahead: Cover with floured cloth; let stand for up to 4 hours.)

Bring large pot of salted water to boil; reduce heat to medium and gently add gnocchi to water. Simmer, stirring gently with wooden spoon, until all gnocchi float to surface, 4 to 5 minutes. Using slotted spatula, transfer to serving dish and sprinkle with butter.

Makes 8 servings.