This makes a lot of pimento cheese, which is the point. Store any leftovers in an airtight container in the fridge.
Pimiento vs. Pimento: Pimiento, Spanish for "pepper," is available fresh from late summer to early fall; canned and bottled are available year-round. Pimento, an alternate spelling, "has been in colloquial use since around 1910," says John T. Edge. Merriam-Webster's Collegiate Dictionary specifies using the spelling "pimento" when used in the term "pimento cheese."
3 (8-ounce) packages shredded extra-sharp Cheddar
1 (4-ounce) jar chopped pimientos, drained
2 tablespoons green onions, finely chopped
2 to 3 teaspoons ground black pepper
1/8 teaspoon ground red pepper (optional)
1/4 teaspoon garlic powder (optional)
Sugar to taste (optional)
1/3 cup mayonnaise
1 pound lean ground chuck
Salt to taste
Ground black pepper to taste
How to Make It
Combine first 4 ingredients and, if desired, ground red pepper, garlic powder, and sugar in a bowl. Stir in mayonnaise, and work into a chunky paste. Store in refrigerator until ready to use.
Remove meat and pimento cheese from refrigerator at least 30 minutes before cooking. Heat a cast-iron or other heavy skillet over medium-high heat. Form 4 (1-inch-thick) patties, seasoning with salt and black pepper. Cook patties 4 minutes per side or until medium, flipping only once. Remove grease from pan. Add buns to skillet, and warm until just toasted. Spread pimento cheese onto warm patties or buns, and assemble burgers.