Rene Spence and Dai Duong are used to being big fish in a little pond. "When we opened in Balaclava, the neighbourhood was desperate for us," says Spence.

Now they're playing with the big kids, opening a second branch of their new-school Vietnamese eatery, Uncle, at the top end of Collins Street last Wednesday.

They've brought over some signature dishes, including the mini serves of pho, along with some CBD-only additions, such as a salad of pressed ox cheek with bean curd and pickled tongue in a spicy satay dressing and silken tofu with green mango, snake beans, scud chilli and candied anchovies inspired by Phan Thiet, a Vietnamese city famous for its fish sauce.

Speaking of fish sauce, Duong is testing a barrel-aged version that makes an appearance in only one dish, a Vietnamese spin on caprese salad with burrata, tomato, puffed rice and pickled papaya.

Unlike the split-level St Kilda version, here it's one level with a rooftop vibe: fold-out windows look on to Bourke Street's treetops and woven cane partitions separate the large dining room (about 100 seats including the central bar area) into more manageable portions with a flirty, tiki vibe – just the ticket for summer.

Open Mon-Sat noon-late.

Level 1, 15 Collins Street, 03 9654 0829