Like most frittatas, the rafanata is going to be based around eggs. Great Italian Chefs recommends using about eight eggs for this dish. There are two other ingredients that really set the rafanata apart though, and those would be potatoes and horseradish.
Epicurious argues that potatoes and eggs are one of the classic food combinations of the world. Think about the obligatory side of starchy potatoes that comes with every egg breakfast at a diner, and you get the idea. Hash Browns and home fries always make a great sponge for all of that rich, runny egg yolk. In the rafanata, the potatoes are mashed before being added and seem to add some body to the otherwise creamy dish.
Great Italian Chefs reports that another important ingredient is horseradish. This spicy root is actually the key ingredient that makes this dish a rafanata and serves as the source of the dish’s name. In Italian, the word rafano means horseradish. The subtle spice of the horseradish goes well with potatoes and adds a nice zest, just as it does when added to a simple potato salad.