This comes from a great Southern cookbook I urge you all to get- even if its forwarded by *ugh* Alton Brown >_<.... The Southern Foodways Alliance Community Cookbook! Makes about 3 cups, and you can use this as a very tasty cheese dip...

Ingredients:

20 ounces grated cheddar cheese (I used sharp, and preshredded in the bag)
1 (4-ounce) jar whole pimentos drained (which you can find easy in your grocery, look in the Mex section)
1/2 to 1 cup Lella's mayonnaise (recipe follows)
1/4 teaspoon onion powder (didnt have, so I used garlic powder)
1/4 teaspoon ground cayenne pepper
1/4 teaspoon Worcestershire sauce
Pinch of sugar
1/2 teaspoon bacon drippings* (VERY optional...it came from the tomato pie I made after, with this)

Place the cheese and pimentos in the bowl of a food processor fitted with a metal blade. Pulse to finely chop the pimentos. (I kinda left them a bit chunky myself...oh well:P) Add 1/2 cup of the mayonnaise and pulse to combine. Add the onion powder, cayenne, Worcestershire and sugar and pulse to mix until smooth. The pimento cheese should be a solid color...the pimentos dont show (oops again) It should be the consistency of thick paste, but if its too dry add more mayo and pulse to combine.

As for the mayo:

1 large egg
1 cup vegetable oil, divided (I used olive oil, we'll see how that goes)
1/2 teaspoon dry mustard
1/4 teaspoon onion powder (again, went with garlic powder)
Pinch of ground cayenne pepper
1/2 teaspoon salt
1 tablespoon fresh lemon juice

Place the egg, mustard, onion powder, and salt in a bowl and use an electric mixer to blend well. The key with making a good mayo is: You need to put in the oil SLOWLY, as this promotes emulsification. With 1/4 cup of the oil, dribble it in as you stir it around. Let it rest (and your arm rest) then, go at it again.

By the time its all said and done it should get good and thick; I happened to add just a touch of heavy whipping cream myself, to make sure that it would. (optional) The other way is (according to the book) if you happen to use a blender with a "pusher", pour the oil into the pusher, and then the oil dribbles into the mayonnaise while you are processing it. Using that method, youll never have the mayo separate.

HOWEVER... a good part of this went on another dish thats coming right up...
Tomato Pie :)

Enjoy!