To make this Chocolate Pie Recipe with Meringue gluten free, use a certified gluten-free deep dish pie crust. Check that the cornstarch, gelatin, chocolate chips, dark chocolate, vanilla extract, and cream of tartar are labeled gluten free or processed in a gluten-free facility. The filling and meringue ingredients are naturally gluten free in many cases, but labels should always be reviewed to avoid hidden gluten or cross-contamination.