1. Finely grate the two cheeses into a large bowl.
2. On a plate, mash pimentos well with a fork till they're very pulpy. Add them to the cheeses along with the pepper, salt and cayenne; mix till well blended. Using a fork, fold in mayonnaise and mash till the spread is smooth, adding a little more mayonnaise if it appears too dry.
3. Refrigerate, covered, at least 2 hours. Will keep up to 1 week.
4. Serving Tips
GRILLED SANDWICHES: Butter each slice of bread on one side and brown the slices, buttered side down, in a skillet. As each pair of slices begins to brown, pack pimento cheese onto one of them and then cover with the other, browned side up. You want the pimento cheese just to heat through; if you leave it over the heat too long you'll have a very oozy sandwich.
APPETIZERS / PARTY IDEAS:
Fill celery stalks, crescents of red or yellow bell peppers or belgian endive spears with pimento cheese.
Make dainty finger sandwiches. Or shape chilled pimento cheese into cheese balls and roll in chopped herbs, pecans or paprika. Or just set out a bowl of the spread with crackers , and have halved cherry tomaoes, capers, and bread-and-butter pickles on the side.