Blend all ingredients with an asterisk (*) in a food processor, and puree until smooth. Pour mixture through either a chamois cloth or cheesecloth and return to food processor while slowly adding oil until smooth.
Blend tomatoes, feta, and mint into a bowl. Add 1 cup of dressing to salad, mix, then add crab and toss to coat crab. Be sure not to break up crab meat; you want to leave as many lumps as possible.