Heat oven to 400°F. Line 12 muffin cups with paper baking cups or grease. In large bowl, combine flour, cornmeal, sugar, baking powder and salt; mix well.
In medium bowl, combine milk, sour cream, oil, egg and chiles; beat well. Add to flour mixture; stir just until dry ingredients are moistened. Fill paper-lined muffin cups 2/3 full.
Bake at 400°F. for 18 to 22 minutes or until toothpick inserted in center comes out clean. Immediately remove from pan. Serve warm.