Combine Jello, vanilla pudding mix, water and lemon juice in a small saucepan over medium heat. Cook and stir until mixture comes to a boil. Remove from heat. Pour into a bowl and chill in the fridge until thickened.
Once chilled and thickened, fold in Cool Whip, blending well. Stir in strawberries.
Pour into pie shell and chill in the fridge until set. Garnish with strawberries and Cool Whip, if desired.
Video
Notes
Make sure the Jello mixture is fully thickened before adding the Cool Whip. If it is still runny, keep chilling before moving to the next step.