In a saucepan, combine water, sugar, salt, and butter. Bring to a boil, then reduce heat to low and add flour. Stir continuously until the mixture forms a smooth ball and pulls away from the sides of the pan.

Remove from heat and let the dough cool slightly. Mix in the strawberry puree until well combined.

Transfer the dough to a mixing bowl. Add the egg and beat until the dough is smooth and glossy.

In a deep fryer, heat oil to 350°F (175°C).

Transfer dough to a piping bag with a large star tip. Pipe 4-6 inch strips of dough into the hot oil, using scissors to cut dough. Fry until golden brown, about 2-3 minutes per side.

Remove churros with tongs and drain on paper towels. Serve warm with strawberry sauce or powdered sugar.