Beat butter and cream cheese at medium speed with a heavy-duty electric stand mixer until creamy. Combine flour and next 2 ingredients in a small bowl. Gradually add flour mixture to butter mixture, beating at low speed just until blended. Shape dough into 24 balls, and place dough balls on a baking sheet; cover and chill 1 hour.
Preheat oven to 400°. Place 1 dough ball into each of 24 greased assorted-shape tartlet tins; press dough into tins and all the way up sides, forming shells.
Bake at 400° for 15 to 17 minutes or until edges are golden. Carefully remove pastry shells from tins to wire racks, and cool completely (about 15 minutes). Let stand at room temperature up to 4 hours before filling, if desired.
Spoon 1 rounded tablespoonful Tomato-Lima Bean Relish into each pastry shell.
Baked pastry shells may be made up to 1 month ahead and frozen in an airtight container. Thaw at room temperature before filling.