How to Make It
Heat oven to 400° F. Heat the oil in a large skillet over medium-high heat.
Add the beef and cook, breaking it up with a spoon until no longer pink, 3 to 4 minutes; stir in the garlic.
Add the sweet potato, spinach, ½ teaspoon salt, and ¼ teaspoon pepper, and toss to combine.
Dividing evenly, spoon the beef mixture onto one side of each piece of puff pastry, leaving a ¼-inch border.
Top with the cheese, fold the dough over the filling, and press firmly to seal.
Transfer the turnovers to a parchment-lined baking sheet and bake until golden brown, 20 to 25 minutes.