Preheat the oven to 400F. In a large skillet, add the butter and squash over medium heat. Saute, stirring, for 5 minutes until the squash has started to soften. Add the tomato and scallion and cook for 5 minutes more until the mixture is very soft but not watery. To the vegetables, add the basil leaves (tear them if they're very large), the lemon zest, the goat cheese, and salt. Stir very lightly, leaving some chunks of goat cheese. Remove the skillet from the heat.

Sprinkle a board or counter with flour, and unfold the puff pastry. Lightly press the pastry with your fingers to flatten just a little bit. On one half of the pastry, make two mounds of the filling. Fold the other half over the filling, then cut in between the mounds of filling to make two pockets. Press the edges of the pastry together with your fingers. Spray each pastry with cooking spray and sprinkle with salt. Place the pastries on a baking sheet.

Bake the turnovers at 400F for 20 minutes or until puffy and golden - cook time will depend on the temperature of the filling. Let cool for 5 minutes, then garnish with extra lemon zest and basil. Cut in half and serve!