Step 1

Preheat the oven to 375 degrees F.

Step 2

In a large, non-stick skillet over medium heat, brown the ground beef.

Step 3

Drain the grease and add the onion, garlic, mushroom, oregano, pepper and salt.

Step 4

Cook, stirring for 2-3 minutes until the vegetables have softened. Stir in the spinach and feta and cook for another 1-2 minutes.

Step 5

Remove from the heat.

Step 6

On a lightly floured surface, unroll the two sheets of puff pastry.

Step 7

Cut each piece into three long, equal strips. Lightly roll each out a bit thinner with a rolling pin.

Step 8

Place three of the pieces onto a parchment lined cookie sheet.

Step 9

Divide the filling between the pieces of pastry, leaving a half inch space around the edges.

Step 10

Place another strip of pastry over top of the filling and press the edges to seal them.

Step 11

Crimp the edges with a lightly floured fork and cut slits into the top of the pastry to vent it.

Step 12

In a small bowl, whisk together the egg and water and lightly brush the three pastries with the egg wash.

Step 13

Bake for 25-30 minutes until the pastry is golden.

Step 14

Serve warm with tzatziki sauce.

Step 15

To make the tzatziki sauce, stir together the yogurt, cucumber, garlic and dill until combined and refrigerate until ready to use.