Quick puff pastry with grated frozen butter, and a sour cream version

Cut the cold cubed butter into the flour and kosher salt with a pastry blender, two knives or hands, until the butter is pea-sized.

Add most of the ice water and mix with a wooden spoon, adding the rest if too dry, until crumbly but cohesive.

Turn out onto an unfloured surface, bring into one ball, wrap in plastic and refrigerate 30 minutes to hydrate the flour and keep the butter cold.

Roll out to about 12 by 4 inches and fold in thirds like a letter; repeat until semi-smooth, three rolls and folds here, without building too much gluten.

Return to the fridge for a few minutes while grating frozen butter, by hand or with a food processor grating attachment. Toss the grated butter with a tablespoon of flour.

Spread about half a stick of grated butter over the rolled-out dough and fold it like a letter; roll and fold twice, add another layer of grated butter, then a single fold and two more roll-and-tri-folds.

Refrigerate another 30 minutes so the butter stays cold.

variation: sour cream puff pastry. Cut two sticks of cold cubed butter into the same flour, add half a cup of sour cream, roll and fold until cohesive, chill 20 minutes, roll and fold three more times and chill 20 minutes more.

To test, cut rounds, brush with egg wash, sprinkle with salt and bake at 400F for about 15 minutes.