Using a 4-sided box grater, grate block cheeses on the smallest grate side.
In a large mixing bowl, toss together the grated cheese and the crumbled blue cheese.
Sprinkle cayenne pepper over the top of the cheeses.
Add pimentos, juice and all.
Add mayonnaise a little bit at a time. You want it to bind, but not become runny or mushy.
Refrigerate overnight to allow flavors to marry.
Grating by hand is recommended, using the side of grater with the smallest holes. If you use a food processor, you run the risk of having the spread turn to mush. How much mayonnaise one uses is a matter of personal taste. The suggested amount of 1/2 to 1 cup is strictly a gauge. Some cooks may prefer less or more.