Bahn mi sandwiches are the backbone of Hawaii's 20-plus Ba-Le restaurants

IDEALLY, A VIETNAMESE sandwich should be crunchy and soft, sweet and sour. The study in contrasts comes from the two critical ingredients: the French bread on the outside and the pickled daikon and carrots on the inside. The meat -- well, that's almost an afterthought. "In Vietnam, you buy the sandwich, you open it up, you see only pickles -- and a few slices meat," says Thanh Lam, owner of Hawaii's Ba-Le Sandwich and Bakery chain.

Bringing banh mi to the United States has meant accommodating American expectations of more meat, Lam says -- "way more."

The sandwiches are the backbone of his restaurants. The central Ba-Le bakery on Dillingham Avenue produces 5,000 loaves of bread between midnight and 4 a.m. daily for the 20-plus restaurants on Oahu. Most of those become sandwiches, Lam says, with chicken being the most popular.

The pickle mix is the sole pursuit of two workers, for their entire shifts. They make 500 pounds per day.

When Ba-Le first opened 21 years ago, Lam tried to purchase his bread, but couldn't find a bakery that could provide enough. So after just a few months he brought in a baker from Vietnam to teach him the technique.

The goal is a bun that's crunchy on the outside, but light and soft inside, so the sandwich -- with its hefty filling -- isn't difficult to chew. Although it may seem large, eating one shouldn't leave you feeling stuffed, Lam says.

A traditional French baguette has a harder crust and a chewier consistency.

With the Ba-Le sandwiches, the difference is a matter of esthetics, but Lam says in Vietnam the texture could have developed as a matter of cost.

Wheat flour has always been expensive, so bakers supplemented with rice flour, which produces a softer bread, Lam says.

Meat is also costly and kept at a minimum. In fact, for an American-size portion of meat you'd pay extra in Vietnam, he says.

Ba-Le's bread is not quite as light as what you might find in Vietnam today, Lam says, but each foot-long loaf weighs in at just 3-1/4 ounces.

It is the pickles that provide the substance in this sandwich and Lam says he is often asked for his recipe. While he's not inclined to give out the specifics, he will offer this clue: Combine vinegar, sugar and salt -- no water -- to make a brine for thin strips of carrots and daikon. "It should taste very sour and very sweet, little bit salty."

And that's as much of a hint as he's going to provide.

The pickles do have a downside: Daikon is a very smelly vegetable.

Ba-Le has contracts to prepare sandwiches for airline meals, but in the close confines of an airline cabin, Lam quickly learned that his pickles were just too fragrant of a filling.

"The first time we made 200 sandwiches, with pickles. Open up, they all smell because of the daikon. No more."

For the airlines, Ba-Le now makes croissant sandwiches with meat-and-cheese fillings.

No pickles.