WE’RE in the middle of a slightly weird conversation about hangovers when that gentle tugging on my tastebuds turns into a full blown "hello!". I momentarily stop talking and look down at my fork. Yes, there sits a blood-orangey-red fillet of confit trout that looks right, tastes pretty right and has a lovely texture.

What about the fine little salad of anchovy, fennel and samphire – salty, sweetly-balanced, eaten with the trout and hang on – crikey, yes, OK, yes, taken together, actually very delicious. Surprisingly delicious.

Delicious enough anyway to make me lean over and immediately try the spiced onion bhaji that arrived with the white onion soup. It’s crisp, light, crammed with finely sliced pleasures. OK, I’m not going to actually be able to dip it in that soup – though that’s what supposed to happen – simply because that soup is still at the other side of the table. In front of Linda, who is looking at me right now, wondering how the hell her onion bhaji got over here. Onto the fork of a man she has just met, like, minutes ago. For the very first time. Ever. Awkward.

To get you up to speed. I am supposed to be having lunch with Linda and Ian. He can't make it. She can. We have never met, did I mention that? I therefore walk across that plush sunlit square out there, in past the table laden with freshly produced bakery stuff, through the room where Helensburgh ladies drink tea whilst wearing hats, yes, hats indoors, without a single Scooby of who I am eating with today. Not even a surname.

How the waiter laughs as I try to work out which table it is, without revealing my own name. Actually he doesn’t. Turns out, and this will surprise me, there is only one table booked at 2pm. That must be it.

Almost as soon as Linda arrives, and the introductions are over with, so does the food. It starts with a trickle. That trout dish. Two surprisingly good side dishes: grilled hispi (cabbage), fired into life by a ferociously moreish sobrasada butter; baton-sized chips that aren’t the usual waterbombs, but golden, crisp, crumbly potato inside.

Then the trickle becomes a flow. A main course of rolled pork fillet rocking to a powerful ham-studded cassoulet arrives, a slice of unctuous, garlicky rolled sausage alongside. This, incidentally, not only looks wonderfully appetising but delivers those crash-bang-wallop flavours that usually only appear when someone has thought very, very hard about what’s going on a plate.

Crikey, I thought this was going to be cafe food.

Within minutes of the cassoulet arriving I’m peering curiously towards that open kitchen that I hadn’t even noticed when coming in.

There are people in whites behind the open counter, a feel of organised bustle, a guy standing in the middle probably directing operations.

The standard of presentation here, so far anyway, is flawless. Take this cod fillet – a dip in a creamy white plate holding a caramel-coloured and just-from-the-pan crust on a fat, juicy fillet, tiny white mushrooms, a few sprigs of samphire, both perfectly and microscopically tweezered on top. And are those micro leaves sage? I don’t want to come over all Strictly here but this is a seriously professional plate of food.

The fish separates into large creamy flakes, steam rising gently, a softly, sweetly, savoury cast to the saffron sauce, a crispness to the skin.

By gum, I say to Linda, I don’t care how much the supplements are, and there are supplements on the £16.50 for three courses lunch menu, we’re in Michelin territory.

A freshly-baked clafoutis comes to the table next, still cooking in its small steel pan, a spicy, full-flavoured salted caramel ice cream alongside.

Seriously good. And so far seriously under the radar. Try it before the word gets out.

Sugar Boat

30 Colquhoun Square, Helensburgh (sugarboat.co.uk, 01436 647522)

Menu: Hispi with sobrasada butter, crisp tongue and green sauce, pan-fried cod with heritage potato – it’s interesting. 5/5

Atmosphere: Cafe-cum-mezzanine restaurant feel is a bit unsettling at first but pleasant and relaxing upstairs. 4/5

Service: Flawlessly genial and friendly in a grown-up fashion and happy to chat over dishes as they arrived. 5/5

Price: Surprisingly the £16.50 for three-course lunch is well worth it – even with supplements for the cod and trout – the quality is so high. 5/5

Food: Not a foot wrong in a Michelin-quality meal with some great dishes including confit trout, pan fried cod and fresh, hot clafoutis. 9/10

Total: 28/30