Preheat Oven: 400 F
Lightly spray inside of 12 regular size muffin cups with cooking spray. Gently press a wrapper down into each cup to line bottom and about 1/2-inch up sides. Bake, uncovered for 5 minutes. Remove from oven. (Wrap remaining wrappers securely and refrigerate for use another time.)
Meanwhile, combine eggs, sour cream and oregano in electric blender container. Whirl on high speed to mix. Stir in chiles. Spoon equal portions into each wrapper lined muffin cup. Bake uncovered for 10 minutes, or until filling is set.
Remove from oven. Serve the Chile Rellenos Tartlets while hot.
Per serving: 37 calories, 2 g protein, 1 g fat, 5 g carbohydrate, 69 mg sodium, 37 mg cholesterol.