In a bowl combine strawberries, jam, and zest. Flatten bread with the palm of your hand or a rolling pin. Mound 1 heaping tablespoon of the strawberry mixture on the center of the bread. Fold bread over strawberries to form a triangle. Brush both sides with melted butter. Place the turnovers on a sheet tray and bake in a 400 degree oven for about 5 minutes per side until golden. Dust with powdered sugar and serve with sour cream.
Variation: Spread center of bread with 1 teaspoon of peanut butter plus strawberry mixture.