Creamy Polenta

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.

• Polenta can be made 20 minutes ahead and kept, covered, at room temperature (do not let stand longer, or it will solidify).