Spinach Gnocchis - cooking recipe

Ingredients

1 3/4 lb. fresh spinach (large stems removed)
7 Tbsp. unsalted butter
1 Tbsp. onion, minced
3 Tbsp. Prosciutto, minced
1 c. Ricotta cheese, lightly beaten
1/2 c. all-purpose flour
3/4 c. freshly grated Parmesan cheese
1/2 c. freshly grated Pecorino Romano cheese
1 egg, beaten
salt

Preparation

Heat 1/4-inch of water in a large saucepan over high heat until boiling.
Cook spinach, tossing quickly until wilted, about 1 minute.
Drain and allow to cool slightly; squeeze out as much liquid as possible.
Chop very fine and set aside.