HEAT oven to 400°F. Beat shortening and cream cheese in large bowl with electric mixer on high speed until fluffy. Beat in flour and salt until dough forms. Press onto bottom and sides of 10-inch cast iron skillet or 9-inch pie plate. COMBINE rhubarb, strawberries, sugar, oats and cornstarch. Place in prepared crust. Fold edges of dough over rhubarb filling. BAKE 40 to 45 minutes or until golden brown.