Blueberry phyllo strudel with yogurt sauce

Put half the blueberries in a saucepan with the sugar, cornstarch, lemon juice and butter; heat over medium until melted and thick, mashing some berries.

Turn off the heat, stir in the remaining blueberries and set aside.

Lay one phyllo sheet at a time, drizzle with butter and sprinkle with a tablespoon of sugar; stack six sheets, leaving the top layer unbuttered.

Spoon half the filling into the centre, butter the edges so they seal, sugar the edges, roll up and press the edges down.

Transfer to a baking tray lined with parchment paper. Repeat with the second batch of phyllo and filling.

Brush the tops with plenty of butter, sprinkle with sugar, tuck the edges in and poke slits in the top.

Bake at 350F about 45 minutes, until crispy and golden all around. Cool before serving.

Wrap leftover phyllo in plastic wrap; it keeps almost a week in the refrigerator.

variation: freeze one strudel unbaked, wrap tightly in plastic wrap or parchment and foil, and bake from frozen a couple of minutes longer.

Push any escaped filling back in and slice to serve.

Whisk Greek yogurt with powdered sugar to taste for the sauce.