Dining out again is so close, I can smell it. In the meantime, this almost-review is on a new fish-and-chipper in Rose Bay, even though it's little more than a cool takeaway with a few stools. Why?

Because it's from the team behind the pioneering Saint Peter in Paddington, where chef Josh Niland built his reputation trying to use every single part of the fish (cue fish eye crisps, fish bladder snacks, cod fat chocolates). Because he then opened a fish butchery that treats fish in much the same way as a normal butchery treats meat.

And now, he has opened Charcoal Fish, a barbecue fish shop that treats fish in much the same way as a charcoal chicken shop treats chicken.

Like the title of his recently released second cookbook, Niland has decided to Take One Fish. That fish is the sustainably farmed Aquna Murray cod from Griffith – a versatile, clean-tasting, white-fleshed fish that he makes a point of cooking every which way he can, from barbecue to rotisserie to the fryer.

Row upon row of whole Murray Cod hang like beef carcasses in the temperature-controlled dry-ageing cool room, dry-ageing for three days to develop flavour and crisp the skin. This consistent supply means even if the boats can't go out, you can still pre-order a whole butterflied barbecued cod fillet for a weekend lunch ($120 for four to six people). Smart.

The space is modern and slimline, almost all kitchen and servery. Later, there will be tables out on the street, with total seating capped at 26; but at this stage, you queue, check-in, enter, order, exit and wait to pick up.

The barbecue Murray cod fillet ($19) is a beautiful study in contrast; the juicy, delicate flesh protected by sea-salty skin as crisp as pork crackling.

Niland wants charcoal fish to be the star, but don't pass up the fish and chips ($28), because it's rare to have such sweet lobes of white fish trapped inside such a hyper-crisp, golden, lacy shell. Chips are nubbly, skin-on and salty, with a terrific yoghurt tartare and just the right sort of dill pickle on the side.

There's also a salad of rotisserie cod tossed through butter lettuce with avocado and juicy barbecued tomatoes ($28) that tastes as sweet and clean as lobster.

The only other fish – yellowfin tuna – gets the burger treatment with double patties, cheese, mustard and pickles. It's genuinely successful, still tasting of tuna while also surprisingly meaty and smoky.

The jury's out on the fish roll ($22), a fishy pun on its charcoal chicken counterpart with its crisp skin, stuffing and fishbone gravy. The skin is a salty cracker, but the fish gets lost amid a pasty herb stuffing, and gravy turns the soft bread roll into clammy pap.

The counter displays springy salads and cooked vegetables that are generous and packed with flavour, from grilled bullhorn and Turkish peppers, to cauliflower a la ficelle or globe artichoke and beans.

In a town that already does great fish takeaway (Boathouse, Bondi Best, Bottom of the Harbour), Charcoal Fish is something special.

It's not there yet – the breads need more structure and stability, and you could be given a fish roll minus the skin, or a salad without any cutlery – but take into account that Niland's "there" is so much more advanced than anyone else's "there".

In terms of how best to judge it, I asked myself some questions.

Is this a significant redefinition of the fish and chip shop? Yes. Is it delicious? Yes. Is it an initiative worth supporting purely on the basis of sustainability and zero waste? Yes.

How far is it to the beach and will my fish still be crisp when I flop onto the sand? Two minutes' walk, and yes, it was.

If I were to score, what would it get? Ha, nice try. Not until we're fully back in business. Is there anything else like it in the world? No.

The low-down

Address 670 New South Head Road, Rose Bay, charcoalfish.com

Open Wed-Sun noon-3.30pm; 5-8.30pm

Drinks Short but sweet wine list at restaurant prices, plus Matt Whiley (Scout/Re) cocktails as well as local beers, juices and lemonade.

Vegetarian Vegetables and salads are done well enough to be the meal.

Cost About $60 for two.

How to order Pick-up only, no delivery.