First thing, it's helluva noisy here on a Saturday night, and we're more than a little out of place. Essentially, Bar Rochford is, as its name suggests without ambiguity, a bar. It's a deliberately low-key entrance way in the Melbourne Building – so much so that after standing on the pavement looking left and right for a few minutes, we call Bar Rochford to ask them where they are, They don't answer; I'm sure it's way too noisy to hear a phone ringing. But as we're waiting for a pick-up we realise that we're standing directly in front of the door. This, of course, is exactly what bars are supposed to be like now: obscure. If you're looking, it's the door next to Lemon Grass Thai on London Circuit.

The narrow, dark stairs are lit with tea light candles and being ancient and risk averse we wonder vaguely about fire hazards, but we like it at the same time. And upstairs the room is busy, some historic ambience, the windows of the Melbourne Building looking good, high ceilings, a few books and old lamps arranged randomly on shelves. Either someone hasn't bothered to tidy up the concrete beams on the ceiling or it's deliberately half done to go with the Euro tatty-chic style, complete with hanging lights, booths and a general sense of relaxation. The music is muffled and heavy, it sounds like old vinyl records, perhaps of live recordings, and adds to the retro feeling.

We wonder briefly whether Bar Rochford is more bar than restaurant and therefore not a place where you go to critique food closely. But that lasts only as long as it takes for food to start arriving, when it becomes immediately clear that despite the fact many people are here tonight for a drink more than food and despite the tiny kitchen where there's no space for anything to get too complex, the food is a big focus, and very good.

Local Homeleigh Grove olives are a good bar snack and start to dinner. Then comes lamb tartare with crispy Jerusalem artichoke, which is an excellent dish. Raw meat is a challenge for some, and lamb perhaps more than beef, but this is clean and simple tasting, not difficult, the lamb chopped small but not mince-small and clearly very fresh. The Jerusalem artichoke is an inspired touch, funky and smokey, and the thin toasts also are great – super salty, but that's right with the raw meat.

The challenging dish comes next, a chicken liver parfait. Chicken liver is about as difficult as it gets for me, with this nagging feeling liver is not an organ meant for eating, and this version doesn't shy away from those intense pungent liver flavours. The parfait is fresh, light and very pink. The cherry compote is strong with cinnamon and a good accompaniment, and "that's the burnt toast", the guy says as he brings it to the table. It is supposed to be burnt and it is, but I think we're no longer supposed to eat burnt toast. It's not supposed to be good for you, so it might sound cool and the entire dish might be on target, well handled and highly appealing to many, but I'm not eating the toast.

The wagyu is really good meat, a substantial service, cut thick. Cooked rare – just charred on the outside, and served with an anchovy mustard dressing. So simple, so good. The chips that our children order (yep, the only children in the place – it's not really a family eatery) are good, with excellently fresh garlic aioli.

The pumpkin dish is ridiculously simple, in a good way. Just a wedge of roast pumpkin, skin on, roasted but still firm, with fresh parsley, nuts and seeds, and something contributing heat, served on yoghurt. I love this simplicity and the confidence and care that has marked every dish tonight. It's modern without being derivative.

So, too, with the dessert. There's only one on the menu – seems to be the thing at the moment – and it's a good one. Orange "posset", a big dollop of thick orange cream with orange shavings on top, old-fashioned in name, up-to-date and startling citrus to taste.

Service has been timely and focused, with only one moment of hesitation on our part when the guy slips into the booth with us to explain the menu – but I guess this is par for the course now and it's true we might have struggled to hear if he hadn't been on our level.

The wine list is reasonably brief and well chosen, with a focus on the lesser known and the more interesting. Locally, it's Nick O'Leary's 2014 tempranillo and Bryan Martin's Ravensworth Seven Months white blend. And there's a focus on whiskies – a long list of them.

Bar Rochford is a slightly confusing mix of bar and restaurant, compounded on our visit by it being a Saturday night, so you need to be prepared for that. But it has nailed the food and wine and is the best newcomer I've visited for some time.