The onions need to be sliced as thinly as possible so they crisp nicely. If served as a first course as part of a formal dinner, arrange the beef in a fan shape on the edge of a smaller serving of greens. Then decorate the combination with the onions.
250 g rare, cooked steak, cut 3/4" square by 1/8" thick
Recipe preparation steps
Combine the vinegar and oil with a whisk. When emulsified, combine with "cornichon" (gherkin), shallots, and chervil. Combine half the vinaigrette with the beef and set aside. Set remaining vinaigrette aside.
Heat oil to 1325ºF for deep-frying. Dust onions with a small amount of flour. Fry onions briefly, in small, batches, until they start to color. Drain well on paper towels and set aside.
Combine salad greens with the remaining vinaigrette, salt and pepper. Divide on serving plates. Divide beef on salads and top with onions.