Place onion halves, cut side down, in a shallow pan. Bake at 425°F for 30 minutes or until onions are slightly soft when pinched and their cut sides are blackened.
When cool enough to handle, discard onion skins and trim stems. Place onions in food processor with oil, vinegars and red pepper flakes. Process in two or three 2-second bursts or until coarsely chopped.
Add olives and oregano, and process 2 to 4 seconds just until chopped.
This recipe was submitted by one of our readers and has not been tested by our food editors. We are not responsible for errors in this recipe, but if you find one, please let us know.