Peel and dice your apples and place in a large bowl. Toss in lemon juice and set aside.
In a medium saucepan, add the brown sugar, granulated sugar, cornstarch, cinnamon, nutmeg, and water.
Heat over med-high heat until the mixture comes to a light boil. Reduce heat to medium and mix in the apples.
Allow the mixture to simmer for 10-12 minutes until you can pierce the apples with a fork.
Allow to cool to room temperature, then place in the refrigerator for 2-3 hours until thickened. I recommend making the filling a day before you need to serve the pie.