1. Arrange the racks in your oven so that, when loaded with the trays, there will be at least three inches of space on the top and bottom of the oven.
2. Preheat the oven to the lowest temperature setting and line the cookie sheets with the parchment paper to prevent the produce to be dried from coming into contact with the metal.
3. Place the Pre-treated produce onto the parchment paper in a single layer, being careful to leave room between each piece.
4. Arrange the trays on the oven racks, leaving three inches between the trays and the sides of the oven.
5. Heat the produce for one hour, and then turn the produce. Rotate the trays in the oven as your take each tray out to turn the produce, bringing the bottom tray to the top, lowering the top tray to the middle and placing the top tray on the bottom rack. Repeat this process again in 45 minutes or so to assure that all three trays get a time on the top rack.
6. After three hours or so, you should start to see that the produce is loosing quite a bit of moisture, and, depending on the produce being dried, could be done.
NOTE: Using a convection oven will speed up the process considerably so make sure that you check the produce in frequent intervals to turn and rotate the trays. I recommend that you check the produce the first couple of times after 30 minutes, and proceed to 15 minutes intervals after that.