Now that Chinese New Year feasts are over, what do you do with all those rounds of gau that friends and relatives gave to you for good luck?

The glutinous sweet treat, made to symbolize the blessings of families sticking together, soon presents a dilemma like leftover turkey after Thanksgiving, except that you can’t make sandwiches or soup from gau.

Japanese families can face the same problem with fresh mochi, similarly sticky and symbolic, from traditional New Year’s Day celebrations. Within a few days, gau and mochi get hard and start growing mold. Those who can’t bear to waste anything will pop theirs into the fridge or freezer, where it could be forgotten for months.

But you can give it back its bounce.

After it’s been defrosted, a common solution is to steam or microwave it, but there are downfalls: Steaming turns gau and mochi into soft, formless blobs that stick to the container, and the microwave tends to turn chewy, glutinous items into rubber in seconds.

Lynette Lo Tom, a Crave columnist and cookbook author, remembers an old method passed down through local Chinese families, developed before the microwave and toaster oven became standard issue in home kitchens.

“Nowadays, when people see mold on gau, they just throw it away. When I grew up my grandmother would cut off the mold, cut the gau into slices, dip it in egg and fry it in butter, or sometimes oil,” she said.

My mother used to do the same thing, and it’s as simple as it sounds. For seven to 10 slices of gau (about 1-1/2 by 2-1/2 inches each), beat one egg — don’t add water or anything else. Coat each slice, fry it over low heat in butter for a few minutes, then flip it over for a few more minutes. Pour any leftover egg over all the slices to create more crispy edges.

The caramel-like smell of the gau browning slowly in butter is an aroma that takes me back to a time when treats were often humble concoctions.

Lo Tom said the super softness of the gau contrasts with the crispy edges formed by the egg coating, an end product that some people prefer to fresh. “It was a different kind of delicious. The texture was different. Sometimes I remember you would distinctly want it because the edges were so crispy, almost like fried.”

She suspects that egg was used because that’s what was at hand. “In the olden days, you had chickens and eggs in your yard.”

Back then, Lo Tom said, refurbishing gau was worth the trouble because it took so long to make, and nothing went to waste.

“Hawaii was made up of immigrants and everyone was so poor. You use everything you have; if you can’t eat it fresh, you have to dry, salt, preserve, cure or something to make it last.”

Waipahu resident Ethel Oshiro said her family always pounded their own mochi when she was growing up in Haiku, Maui. When the mochi got old and hard, they would cut off the moldy parts and reheat it in a pan of water or oil, then season it.

For those who tucked away some unflavored, unfilled mochi after New Year’s this year, this is her process: Put enough vegetable oil in a pan so it will cover one-third of the mochi for a semi-deep fry. Fry over moderate heat until the outside is crisp golden brown and the inside is soft. Crack the crunchy surface with a chopstick, and pour shoyu over it, or use sato shoyu (mixed with a little sugar).

Another preparation: Place slices in a pan with water covering the slices three-fourths of the way; bring to a simmer and cover for about three minutes. When a chopstick goes easily through the center of a piece, it’s done. The mochi will be very soft, so don’t try to flip it over. Take each piece out dripping wet (don’t drain it) and roll it in a mixture of kinako (soybean flour) and sugar, about 1:1, or to taste.

For a cross-cultural snack, why not coat gau in kinako before dipping it in egg? Or try coating mochi with egg, dashed with sweetened shoyu. The possibilities are endless!