Combine the lemon and 4 cups water in a large bowl. Place the sliced apples in the water to keep them from browning.

Melt utter in a large skillet over medium heat Drain water from apples and place them into the hot skillet and stir for about 2 minutes.

Add brown sugar and cinnamon to skillet with apples and stirr for about 2 more minutes.

Stir together cornstarch and tablespoon water. Pour into the apple mixture and mix well. Cook until sauce has thickened ( about one minute). Remove from heat and cool slightly.

Preheat the oven to 400°F

Unfold puff pastry sheets, Trim each sheet into a square and then cut each large square into four smaller squares.

Spoon apple mixture onto the enter of eah square and then fold from corner to corner making a triangle. Press the edges together to seal .

Place turnovers onto a baking sheet (You may want to lightly grease sheet) leaving a little space between each one.

Back for 25 minutes or until turnovers are puffed and lightly browned. Cool before glazing.

To make glaze mix confectioners' sugar, milk and vanilla into a bowl. Adjust the thickness by adding sugar or milk accordingly.

Drizzle glaze over turnovers.