Start to finish: 1 hour
1 sheet frozen puff pastry, thawed (each 17.3-ounce package contains 2 sheets)
2 pounds fresh strawberries, hulled and halved
1 pound fresh rhubarb, cut into 1-inch pieces
½ cup plus 1 tablespoon sugar, divided
Pinch of salt
Juice of 2 lemons
½ cup cornstarch
Heat the oven to 400 F. Coat a 9-by-9-inch baking pan with cooking spray.
On a lightly floured surface, roll out the thawed sheet of puff pastry to 9-by-9-inches. Set aside.
In a large saucepan over medium-high, combine the strawberries, rhubarb, ½ cup of the sugar and the pinch of salt. Heat, stirring gently now and then, until the fruit is tender and bubbling, about 7 to 8 minutes.
In a small bowl, combine the lemon juice and cornstarch. Stir into the simmering fruit. Simmer, stirring constantly, until thickened, about 1 minute.
Spoon the mixture into the prepared pan. Place the prepared pastry over the top, then sprinkle with the remaining 1 tablespoon of sugar. Using a paring knife, slice a couple of vent holes in the pastry. Bake for 25 to 30 minutes, or until the pastry is golden brown. Spoon into bowls and serve warm or at room temperature.Nutrition information per serving: 150 calories; 15 calories from fat (10 percent of total calories); 2 g fat (0 g saturated; 0 g trans fats); 0 mg cholesterol; 36 g carbohydrate; 2 g protein; 4 g fiber; 60 mg sodium.