Talk about location. It's a Sunday afternoon and we're winding down the steep pathway to Cottage Point Inn, a former boathouse set deep in Ku-ring-gai Chase National Park. Lemon myrtle lines a rocky staircase and the sun has battled through low-hanging clouds to turn Cowan Creek an electric blue.

It's the closest thing Sydney has to those coastal ristorantes that Rob Brydon and Steve Coogan visit in The Trip to eat spaghetti vongole and impersonate Roger Moore. The kind of places where kids do backflips off pontoons while chiselled Italians share platters of charcoal-kissed squid, their hair still wet after spearfishing lobsters.

I probably wouldn't be splashing about at Cottage Point with all its seaplane activity, but a bit of grilled seafood would be nice with the view. Oysters, too, obviously. An unfussy lunch since nature's done the heavy lifting, starting with champagne to recharge after a one-hour slog from the city.

The fizz is no problem: creamy Bonnaire Tradition Brut is $32 a glass or there's a $16 pour of King Valley prosecco. Rock oysters ($6 each) are cold and clean and mercifully free of granita and other cheffy toppings.

But then – ah, damn – it's a "tasting menu". I don't want to "taste" in a spot like this: I want to eat and draw straws for who has to drive home.

The last time I was here it was a set-menu affair, too; one with quenelles and curds and miso caramels, and edible flowers on every second course. But chef Steve Hetherington took over the pans in August after more than a decade at Woolloomooloo's Manta, which moves whole mud crabs like Kentucky moves chicken. Perhaps he'd bring a few crustaceans north.

There are no muddles at Cottage Point Inn today, though – not like there were in the 1980s when the weatherboard joint would host live jazz and seafood buffets heaving with octopus, mussels, flounder and whiting.

Instead, there are green ants topping wagyu bresaola, which must be a hoot for people fond of insects that don't taste like very much. Milky stracciatella cheese and cubed watermelon sit underneath the air-dried beef – it's an odd but not unpleasant combination when unified with balsamic vinegar.

Next, three duck tortellini (dry) in a bold-flavoured consomme (quite good) that might have been nice by the fireplace in June, but doesn't quite take off on a sunny spring day. 

I'm also surprised to see Jerusalem artichoke making an appearance this far the other side of winter, pureed and plated with crisp-skinned Murray cod. It's an outstanding bit of fish, beautifully cooked so it falls apart in meaty, snow-white lobes. Samphire adds salt and crunch and the course is very much the highlight of the day, perhaps my week.

Wild garlic-laced risotto is dolled up with a clump of elderflower that only gets stuck in your teeth, but is otherwise pleasingly al dente and textured with bronzed pecans and fried shallots.

Maybe the kitchen is on to a good thing with the set-menu direction, despite all the ants and silly flowers. Maybe I just need to go with the flow instead of writing a wish list in my head, like some Twitter nerd upset with the latest Star Wars: "Pfft. Well this is how I would have done it."

Maybe. Except a brick of pork belly is so overcooked it could be used to chock a fire door. Too-sweet splodges of apple and celeriac on the plate don't make it any better.

Dessert is a dark chocolate brownie. Chewy. Rich. Fine. But its crowning, blood-orange sorbet and dehydrated citrus teeter things into a zone between cloying and "Can we just get the bill?"

Is all of this worth the drive from Sydney or punt from Patonga to star in your own episode of The Trip to Ku-ring-gai? Yes. There's still a lot to like, apart from the spectacle of wobbly windsurfers and towering bushland. Service is seamless and mellow, and staff are quick to offer mohair blankets for your knees when the breeze picks up. Handmade ceramic plates are a classy touch and the cellar has plenty of bottles to keep the afternoon interesting.

I have faith Hetherington will find his groove over time, hopefully ditching the big swings and trick shots of previous chefs. If the set menu is there to lock in a spend of at least $140 per person, surely that mark can be hit with a few whole fish and sides of beef to share? The kitchen knew the score with that buffet in the 1980s: keep it simple and they will come.

Vibe: Ambitious cooking in a magical setting

Go-to dish: Murray cod with Jerusalem artichoke and samphire (as part of a set menu)

Drinks: Savvy, Australian-dominated list with a few gems and plenty of half-bottles

Cost: Five-course tasting menu $140; eight-course menu $180

This review was originally published in Good Weekend magazine