Slice the eggs in half. Remove the yolks to a separate bowl. Use a fork to mash the yolks until they are very fine crumbs. Reserve 3.5 tablespoons of the yolk.
Add the yolks, mayonnaise, and mustard to the bowl of a food processor or blender. Pulse until very smooth and free of lumps.
Add the processed filling to a small bowl. Fold in the pimento cheese.
Fill each egg half with mixture. You should not have any filling remaining.