Cut a thin slice from the bottom of each potato to form a flat base; brush potatoes evenly with oil, and place on a baking sheet.
Bake at 350° for 45 minutes or until tender. Remove from oven, and let cool slightly.
Cut a thin slice from the top of each potato. Carefully scoop out potato pulp into a bowl, leaving shells intact. Add shredded Cheddar cheese and next 5 ingredients to potato pulp in bowl, and beat at medium speed with an electric mixer until smooth and creamy. Stir in green chiles. Spoon mixture evenly into each potato shell, and place on baking sheet.
Bake potatoes at 350° for 20 minutes or just until lightly browned. Garnish, if desired.