In a blender or food processor, combine the egg, mustard, salt, garlic, and the ground cumin seeds. Process it briefly to blend. With the motor running, add the vegetable oil in a slow, steady stream. Pour in the lemon juice and then slowly add the olive oil until the aioli is emulsified. If the mixture seems too thick, add a spoonful or two of water. Scrape the aioli into a bowl and stir in the whole cumin seeds. Cover and refrigerate.