Heat up 2 tablespoons of olive oil in a large skillet. Add onions, sugar and salt to the pan and cook the onions over low heat for one hour until a rich golden color is achieved.
Remove the onions from the pan and cool in the refrigerator completely.
Once cooled, add the onions to a food processor along with the dill, mayonnaise, Greek yogurt and pepper. Process until the desired consistency is reached.
Serve this dip with raw vegetables, potato chips or on top of baked potatoes. Enjoy!