In a small saute pan add the olive oil, chopped onion and minced garlic.
Saute over medium heat until the onions have caramelized.
In a small mixing bowl, combine sour cream, mayonnaise, garlic powder, sea salt and caramelized onions.
Refrigerate for 2 hours before serving to allow flavors to meld (although it's pretty fantastic when freshly made too!)
Store leftovers (if there are any) in a covered container in the refrigerator.