Cut 1/2 inch off pointed end of onion; peel onion, leaving bottom stem. Cut 1-inch diameter core out of middle of onion. Using very sharp, large knife, cut through center of onion to about three-fourths of the way down. Turn the onion 90 degrees and cut it again in an X across the first cut. Keep cutting the sections in half, very carefully until the onion has been cut 16 times. Do not cut down to the bottom of the onion. Spread the "petals" of the onion apart. Coat onion with cereal mixture, separating petals and sprinkling dry coating between them. Dip onion into egg mixture, then into cereal mixture again. This double-dipping ensures a well-coated onion; some of the coating will wash off when frying the onion.