Bring a pot of salted water to a boil. Turn the dough out unto a floured surface. Roll the dough out to about 14-inch rectangle and 1/4-inch thick. Cut the dough into 1-inch squares. Add the dough to the boiling water and cook for about 4 to 5 minutes, or until the dough floats for 1 minute in the water and is fully cooked. Remove and drain on paper towels. Season with salt. Meanwhile, melt the butter in a large saute pan. Add the onions. Season with salt and pepper. Saute until tender, about 3 to 4 minutes. In a large mixing bowl, toss the dumplings with the onions and cheese. Toss well. Season with salt and pepper. Spoon into a serving bowl and garnish with parsley. Serve warm.
In a mixing bowl, combine the water, oil and egg. Mix well. Add the salt and 3 cups of the flour. Mix until the dough comes together and form a smooth ball. **If the dough is too sticky-add a little more flour, about 1/4 cup at a time. Cover with plastic wrap and allow to rest for 30 minutes.