Source: Esther Surdut's New Pesach Cookbook- Cape Town South Africa, 1999
Gnocchi: Boil the potatoes till tender. Drain, peel and mash. Add the egg, salt and most of the flour; mix until you have a soft dough that is not sticky and is easy to work with. Rest the dough for 1/2 hour.
Divide the dough into 4 portions (or more) and roll each portion into a long sausage shape about 2 cm thick. Cut into 2.5 cm slices and press against the prongs of a fork to make indentations on the gnocchi. Bring a large saucepan of lightly salted water to the boil.Add gnocchi a few at a time until they rise to the surface. Remove with a slotted spoon. Place in a serving dish, add the pesto and garnish with extra grated cheese and some olives.
Pesto Sauce: Blend all the ingredients together in a food processor. If the sauce is too thick thin down with a little water.