It all started at I Love Sushi. We were smacking our lips over a perfectly broiled hamachi kama and a wildly slimy sushi roll covered with tororo, that fresh-grated mountain yam, when the approving auntie who owns the tiny place in Samsung Plaza said, "You like natto? You come back, try our natto bowl. It's not on the menu, but we can make it for you."

What? Not on the menu? We feel like we've just glimpsed a secret society. What have we been missing out on? Where else can you get stuff off the menu?

We delve — and make some discoveries. Not many restaurants entertain off-the-menu requests, unless you know the owner or manager. Those that do are smaller, though bigger places will sometimes bring back old-time favorites for customers who ask. And if you're at an ethnic restaurant, you have a pretty good shot if you request a simple dish from the old country.

Everyone we called about an off-menu item got the same final question: Can anybody come in and order it? Everywhere below, the answer was yes.

LONGHI'S

Ala Moana Center, 1450 Ala Moana Blvd., 947-9899

All you have to say is "The Quintessential." It's Longhi's version of mac and cheese ($14 at lunch), long since gone from the menu. but always simmering on a back burner for customers who ask. Since the kitchen usually doesn't have macaroni, you get whatever short pasta is on hand, tossed with a tomato-cream sauce with two cheeses melted in. Not sticky-gummy, like most baked mac and cheeses, but al dente, rich and velvety.

Note: The Quintessential is too big and rich for a single serving. Get a salad or appetizer and split with someone.

The 'ahi carpaccio ($19) is a texture-fest with a thin sheet of 'ahi sashimi on toasted French bread that's sitting on a salad accented with capers and tomatoes. It's on the menu, but it's the extra, off-the-menu touch — a good sprinkling of crunchy crushed macadamia nuts — that makes it a standout. "It's tossed in olive oil and lemon juice, and the greens are a little bitter," Longhi's pastry chef Ed Morita says, "so I like to add mac nuts for sweetness."

MAILE'S THAI BISTRO

Hawaii Kai Towne Center, 6700 Kalaniana'ole Highway, 394-2488

We knew the standard pad thai. We loved the shoyu-rich pad see ew. But until Maile Sayarath suggested her off-menu pad khi mao ($9.90), we'd never heard of these noodles. If you love shoyu, basil and spice, this will be your new favorite stir-fry.

One more thing: Maile's kitchen staff likes Laotian favorites, so if you're craving hard-core Vientiane-style flavorings like fishy fish sauce — which may be more like Filipino bagoong than Thai or Vietnamese versions — see if they'll make you some Laotian green papaya salad. And don't say we didn't warn you.

IZAKAYA NONBEI

3108 'Olu St., 734-5573

If you're a natto and sashimi lover, your taste buds can know no greater rapture than this. Available some days at this Kapahulu izakaya, yamitsuki (literally, "addicted to," $7.50) combines the whipped, fermented beans with a mince of 'ahi, salmon, squid, tako and aji. You wrap a spoonful in briny-crisp nori and pop in your mouth with no need for added shoyu.

SUPER PHO

3538 Wai'alae Ave., 735-9989

Yes, you can eat soup with pineapple. It's called canh chua ($13.99), which means sour soup in Vietnamese. But it's actually tangy-sweet, and it's loaded with crunchy veggies, tomatoes and catfish fillets, all sprinkled with the tiniest crisps of fried pork rinds. All of which is on the menu. What's not is the side of fish sauce and chilies: Do as the Vietnamese do and dip the fish in this for a salty-hot kick.

One reason we love this place is the easy attitude. Another time we were jonesing for Vietnamese-style jook with beefy bits. "No, we don't have," they said, "but we'll make for you."

RYAN'S GRILL

Ward Centre, 1200 Ala Moana Blvd., 591-9132

A while back, Ryan's menu featured this seared 'ahi linguine ($16) — two small fillets cooked to just-pink in the middle, crusted in different peppercorns and drizzled with beurre blanc and lemon zest, all sitting atop noodles dressed in clam juice, butter and more lemony tang. Regulars request it so much it sometimes reappears as a special. At the moment, it's off the menu, but all you have to do is ask.

PALAZZO RISTORANTE ITALIANO

Aiea Town Square, 99-080 Kauhale St., 485-8688

The charm of this Vietnamese-owned Italian eatery is not only in finding an Old World throwback in an 'Aiea strip mall, it's also in their willingness to cook any dish any way you want it. Meatball spaghetti with white sauce instead of marinara? No problem. Chicken pesto linguine with fresh spinach instead of carrots ($15.90)? That's what we got: tons of tender chicken in a light pesto loaded with spinach, zucchini and mushrooms, the sauce permeated with fresh vegetable essence.

I LOVE SUSHI

Samsung Plaza, 661 Ke'eaumoku St., 951-0848

We're back for auntie's natto bowl ($11.95), which turns out to be a medley of natto, tororo and minced 'ahi on a bed of rice. The natto is the soft white kind, its flavor pounds through the 'ahi while the tororo practically aerates the mix with freshness, and you don't need shoyu. Together with auntie's miso soup and side dishes, it's filling, rustic comfort food.

We are totally satiated. Initiated at last into a world of hidden dishes rife with possibility. If you know of any more off-menu specials, let us know.