One way to make green gnocchi is to combine spinach and ricotta, as described in
The choice of potatoes for the dough is critically important, just as it is in making plain gnocchi. Mealy, baking potatoes or moist, new potatoes must be avoided: Use only old boiling potatoes. If the temptation to add eggs to the dough comes your way, resist it. It is the presence of eggs that makes potato gnocchi heavy, lumpish, excessively chewy. Proper gnocchi must be light and fluffy.
The best sauce to use is a simple, fragrant tomato sauce such as the one. Even more simply, toss the gnocchi with butter and a generous amount of choice freshly grated Parmesan. Or gratinate them thus: Cook and drain the gnocchi and put them in a flameproof serving dish; dot with butter, sprinkle liberally with Parmesan, and place them under a hot salamander or a grill for just the time it takes for the cheese to begin to melt. Don’t keep them too long under the flame or the gnocchi will turn to mush.
© 1986 Marcella Hazan estate. All rights reserved.