CTE Index recommendations on multiple keyed table

Question

I have a View which is keyed on both ChargeID and CustomerID (Charge can be split between multiple customers). The View consists of 2 tables (heavily simplified here, actual tables have ~40 columns each):

CREATE TABLE tblCharge (ChargeID int NOT NULL, ParentChargeID int)
CREATE TABLE tblChargeShare (ChargeShareID int NOT NULL, ChargeID int NOT NULL, CustomerID int, TotalAmount money, TaxAmount money, DiscountAmount money)

The View just joins these both together:

CREATE VIEW vwBASEChargeChargeShareCustomer AS
Select ParentChargeID, b.* from tblCharge a inner join tblChargeShare b on a.ChargeID = b.ChargeID

I then have a CTE for getting the subcharges for the parent:

WITH RCTE AS
(
SELECT  ParentChargeId, ChargeID, 1 AS Lvl, ISNULL(TotalAmount, 0) as TotalAmount,  ISNULL(TaxAmount, 0) as TaxAmount,  
ISNULL(DiscountAmount, 0) as DiscountAmount, CustomerID, ChargeID as MasterChargeID
FROM vwBASEChargeChargeShareCustomer Where ParentChargeID is NULL

UNION ALL

SELECT rh.ParentChargeID, rh.ChargeID, Lvl+1 AS Lvl, ISNULL(rh.TotalAmount, 0),  ISNULL(rh.TaxAmount, 0),  ISNULL(rh.DiscountAmount, 0) , rh.CustomerID 
, rc.MasterChargeID 
FROM vwBASEChargeChargeShareCustomer rh
INNER JOIN RCTE rc ON rh.PArentChargeID = rc.ChargeID and rh.CustomerID = rc.CustomerID )

Select MasterChargeID, CustomerID, ParentChargeID, ChargeID, TotalAmount, TaxAmount, DiscountAmount , Lvl
FROM  RCTE r 

So the CTE is joining on CustomerID and ChargeID=ParentChargeID

This works well, but does not perform well on large data sets (millions of Charges).

What is the best way to Index the tables (or view) to get the best performance? (SQL 2008R2 and above)