The trouble with institutions is they can wind up being thoroughly institutionalised. Anoint a restaurant with the "i" word and there's a short-odds chance it will become a fusty museum piece with about as much joie de vivre as Madame Tussauds.

Flower Drum was heading down that road. The menu at the erstwhile three-hatted darling hadn't changed in more than two decades. Most of it was dull. The service was unimpeachable but so phlegmatic the last time I ate there, I was tempted to yell "fire" to see what would happen (I'm guessing they would have gone on silently plating the Peking duck).

It looked like the start of the slow cascade from institution to ignominy, a well-worn path that sees restaurants divested of their Good Food Guide hats one by one before sliding down the rankings and, quite possibly, disappearing forever. It has afflicted many of Melbourne's finest Cantonese restaurants, the ranks of which have whittled away from a peak some 20 years ago to a bunch of faded divas resting on the reputation of their glory days.

But then something strange and marvellously unexpected happened. Flower Drum got its mojo back.

The changes, as far as I can tell, have been instigated by maitre d' Jason Lui, son of executive chef and co-owner Anthony Lui and a young man with a keen sense of contemporary dining beyond the hallowed walls of 17 Market Lane.

The old menu has been mercifully euthanised. You'll no longer find the same encyclopedic document on which the words "sweet and sour" appeared with spirit-crushing regularity. In its place is a far more concise and contemporary collection of dishes that reflect the way people eat now, rather than the way the taxpayer-subsidised business crowd ate two decades ago.

But anyone who has eaten at Flower Drum over the past few years will notice the changes don't end at the menu. For one, it's no longer like pulling up a seat in a comfortable, red-carpeted morgue. The waiters have woken from their coma and are filled with a new sense of purpose and — more importantly — pride. Even the guy who presses the elevator button is full of bonhomie.

"Welcome home" is their new catch-cry — we heard it twice the other night and it might be corny as hell but it's also rather appropriate. Flower Drum isn't so radically altered from its self of old. They've salvaged the best of the menu from the dross, the service remains exemplary and nothing — repeat, nothing — will prevent them playing Richard Clayderman on the stereo.

There's still an off-menu experience but the really profound change is that it's no longer denied to anyone who hasn't already located the secret portal to the wonders of Anthony Lui's kitchen. Twelve months ago, putting the feelers out to go off menu was like asking the waiters for their PIN numbers. Now, ask and you shall receive a willing recitation of what's special that day.

The changes also mean the freedom to kick off proceedings conventionally (and very beautifully), safe in the knowledge that the fireworks will arrive later. On that note, the crayfish omelet ($24) sets a new gold standard for this timeless classic, with eggs of such creamy, fluffy lightness, the beautiful flavour of the crustacean shines through.

Then arrives something startlingly new — noodles composed almost entirely of wild barramundi fillets, augmented only by finely diced Chinese pork sausage and a pinch of dried tangerine zest ($16). Although they're stir-fried with garlic shoots, shiitake mushrooms, bean shoots and capsicum strips, most of the flavour is carried by the noodles. In a word — incredible. There's joy in their texture: firm yet elastic, almost defying their lack of starch binder (this is a gluten-free dish). It's a recent Lui invention and it's a corker.

On to the garfish, stuffed with julienned vegetables and bean shoots and served whole after being fried with a light, non-greasy batter; in a bowl on the side arrives a thick, gelatinous shiitake broth with small pieces of fresh shiitake. The net effect of this improbable combination is magnificent.

Back to a classic with a must-try visit to the drunken squab ($48), the whole fat bird dissected on the plate with the breast meat sliced and fanned out, the better to show off its firm, dense texture, its almost livery taste and its subtle aromatics that contrast beautifully with the alcoholic brightness of the shao xing sauce.

Or perhaps you'd rather try a less refined, more northern Chinese and very wintry dish of lamb brisket (although it's probably two-tooth or mutton) braised with ginger, garlic, red date and water chestnut in a brown sauce with membrane-like sheets of tofu ($55 but as with many dishes here, it's worth asking about a half-serve). On the side, there's a fermented tofu sauce brightened with the finest slices of lemon leaf. Unusual, invigorating and, yes, just a bit challenging.

Even desserts are on a new footing. A special of ginger juice, double-boiled with milk ($9) — the milk curdles so it becomes something like the Chinese answer to panna cotta — is sweet and bracing, yet light and incredibly palatable after a big meal.

The push doesn't stop there. Randolph Cheung (Asiana) has been enlisted to give the wine list an overhaul, his brief to put more emphasis on boutique labels. For the moment, it's a more accessible collection than the average punter might suspect, although it shares the usual Chinese bias towards Bordeaux.

Incidentally, this is the first time I've devoted the page to a re-review. With so many new places, it's always seemed unfair to give the space to restaurants that have had their time in the sun. But screw it. Flower Drum's back and I'm excited.

We drank Grosset Springvale Watervale Riesling (Clare Valley, South Australia), $69

17/20: renewed zest, in and out of the kitchen

Score: 1-9: Unacceptable. 10-11: Just OK, some shortcomings. 12: Fair. 13: Getting there. 14: Recommended. 15: Good. 16: Really good. 17: Truly excellent. 18: Outstanding. 19-20: Approaching perfection.