Bring water and salt to a boil in a 3-quart heavy saucepan, then add polenta in a thin stream, whisking. Cook over moderate heat, whisking, 2 minutes. Reduce heat to low and cover pan, then cook at a bare simmer, stirring with a long-handled spoon for 1 minute after every 10 minutes of cooking, 45 minutes total. Remove from heat and whisk in butter until incorporated.
Serve polenta warm. Do ahead: Cooked polenta can be set aside for up to 20 minutes, covered, before it starts to firm up. If you have leftovers, spread them out in a casserole dish and refrigerate overnight so that they solidify into a firm cake; slice the solidified slab to make a crispy fried polenta appetizer or grilled polenta cakes later in the week. Editor’s note: This recipe was originally printed in the January 2007 issue of ‘Gourmet.’ Head this way for more of our comfort food favorites →
