If you haven't heard of Lillian, that's likely because it's suffering from second sibling syndrome.

For four years we've been hearing about Lucas Restaurants' 80 Collins flagship, Society. That dark and glittering headliner is tough to follow, yet Lillian, a warm and curvaceous European bistro that sits alongside Society, might be the project's dark horse.

Where Society is glamorously imposing with its sharp edges and charcoal tones, Lillian is a study in curves. The wooden bucket seats closely cup rumps in a way they mightn't have been touched in 20 months. Elsewhere, the tan leather banquettes are chubby and yielding.

This may be the more casual side of Society, but the details haven't been skimped on. Smoky taramasalata and potato crisps arrive in fine, fluted silver bowls, as does the hefty stack of Sicilian olives for your martini.

The hype about the whole Society package, which includes private dining rooms and a lounge area where you can drop in for that now-famous martini with its caviar-draped pretzel on the side, has captured the city's well-heeled and bare-ankled elite. And on a Friday lunch, I'd say Lillian has the edge. People are loudly, proudly deep in their cups. 

Lavish touches do come at a price, and while Lillian isn't nearly as expensive as Society, food-wise, you could still have a very merry Christmas on someone else's credit card.

One of the city's most esteemed sommeliers, Loic Avril (ex-Dinner by Heston), has brought some exciting flexibility to the wine list for those with expandable budgets.

Dom Perignon by the glass is a novelty, albeit at $88. The restaurant has its own custom Piper Heidsieck and they're pouring rare wines like Mount Mary's Quintet 2013 cabernet blend ($63 for 75 millilitres).

At the (relatively) more affordable end of the spectrum, the Kanta Adelaide Hills riesling is a beautiful local star, and proves it's not all about power drinking (though it may pinch to pay $17 a glass for a bottle that retails about $25).

Back on the table, however, it's a moderately pitched menu you'll be keen to play on repeat. We start with those hand-cut crisps and smoky tarama fringed with chives, then whole king prawns, cleaved in two, slicked with a fermented chilli aioli and grilled to bring out sweetness and smoke. Wrapped in cool, crunchy duvets of lightly dressed cos leaves, it's a slam-dunk for fiery, refreshing handheld fun.

Every dish, whether it reads like a well-known classic or a newbie, sneaks in a surprise element. We order culatello (salumi made from the sweetest part of the pig rump), which is draped in nicely warmed curls around sweet and spicy pops from fresh sliced grapes and radishes.

Waves of smoked salmon get their textural lift from an almost unrecognisable lace of finely shaved raw cauliflower, which adds a gentle earthy, peppery hit.

There's also a chicken salad, a dish you thought died at the last power lunch of the '90s, but which has risen respectably here in the form of fat-rich thighs, with bold boosts of black sesame crackers, avocado creme and salt-bursts of anchovy.

You couldn't ever accuse this food of being coy. See the intense richness of a potato gratin, possibly the best, buttery layered potato creation in the city right now, all distinct soft layers with golden crunch and a parmesan hit at the end.

Or a blushing veal minute steak that gets serious pep from acidic white anchovies spiked through the vivid salsa verde. Still, those potent flavours are straightforward enough to make dishes sing rather than stifle the great produce at their base.

But a quick word on service. The entire restaurant industry is desperate for staff, so while Lillian, and sister Society, have absolute guns like Avril roving the floors, some very green staff make up the ranks. Here at Lillian, you might get world-class wine-matching, or you may be quite thirsty before your drink shows up. (Hot tip: order by the bottle.)

But the take-home message is this. All restaurants are doing the best with what they've got, and Lillian has a great deal working in its favour.

It's a sumptuous but soft space to celebrate in. It has a menu with the breadth to pivot from power lunch to a party starring a big hunk of Margra lamb (the wagyu of sheep) at night. Add oily glasses of Burgundy, a high-falutin' view over Collins Street and a solid retro revival of cakes and tarts for dessert, and she's got the goods to be a city star.

Drinks: The 10,000-bottle cellar is premium, and priced accordingly.

Cost: Entrees $19-$31; mains $32-$48.50