"We have a very different style of tying empanadas," says chef Anthony Walsh, standing next to his 73-year-old mother-in-law, Elena Arevalo, in a demonstration kitchen high above the Hudson's Bay store on Queen Street West in downtown Toronto. "Usually, every restaurant you go to in Argentina, they have this as a snack," says Arevalo, who believes empanadas should sit on a counter while they're folded, as opposed to Walsh who picks his up and forms them as they hang between his fingers.

Despite their difference of opinion (and technique), Arevalo and her empanadas are, he says, "the heart of Leña," the South American cuisine-focused eatery that Walsh will open this summer in the Eaton Centre location of Saks Fifth Avenue. While Leña's menu is Walsh's creation, Arevalo's influence is evident throughout its signature dishes, authentic ingredients and even the name of the restaurant's bar, Lala. "She's known as Lala, which is slang for abuela, or grandmother," says Walsh.

As personal as this launch is for Walsh, Leña is part of a growing awareness of the South American kitchen around the world. Once known primarily for street-food staples such as ceviche and coxinha, the continent's diverse cuisines and international influences now inspire chefs at home and abroad. Blame Lima's scorching restaurant scene (including Central, Malabar and Astrid y Gastón) and the carnivore nirvana that is Buenos Aires for the current obsession with all things edible from south of the equator.

Arevalo moved to Toronto from Monte Coman, a town in the province of Mendoza, in 1976, bringing along her two children (including Walsh's wife Susana) and a unique way of working in the kitchen. "I'm a pretty good cook, but with Elena, it's not so much a technical thing with this type of cooking," says Walsh. "The portions that she uses are not textbook. There's more garlic than there are onions. Or she's frying parsley first for the sauce, and you just don't do that. But it's been such a fantastic learning curve. It's really changed how I think culturally, being raised the second half of my life in this Latin family, and it's changed how I cook."

Walsh got his start with Oliver & Bonacini Restaurants, the company behind Leña, at Toronto's iconic Canoe in 1995. He now serves as the company's corporate executive chef, which means overseeing 13 different kitchens across Canada. At Leña, he's charged Toronto-born, Lisbon-raised chef de cuisine Julie Marteleira – formerly of O&B's Jump, Auberge du Pommier and Luma -– with heading up the kitchen team.

Aside from the bar, Leña will consist of a street-level lounge, including an octagonal bar, that seats 80 for breakfast, lunch and dinner, and another dining level one flight up that will seat another 80 customers, including space for private dining. The decor by DesignAgency, serving wear and dishes will all be bright and colourful, but simple – innovative without being overwhelming.

That description can also be used to characterize Walsh's approach to South American cooking. "When people think of Argentinian, it's very meat forward," he says. "Argentinian cuisine is new to Toronto – I can think of three legitimate Argentinian restaurants in the city – so I think people are interested in exploring the cuisine."

So while the kitchen will be serving up pork shoulders and jamón, there will also be fresh juices, seafood and sandwiches de miga. "They're quintessentially Argentinian," says Walsh. "They're like an English tea sandwich, but triple layered and pressed like it's a block. You'll have ham and cheese, or ham and avocado."

Given the restaurant's proximity to the office towers lining Yonge and Bay streets, Leña's service will cater to a crowd that needs to be in and out within an hour, but outside of office hours, leisurely family-style meals are encouraged, and brunch will be a focus on the weekends (think fresh pastries, flan, and poached eggs atop those contentious empanadas).

"With my family, it was always about big, long meals," says Arevalo. "And we're always talking about food. At the table we're talking about it non-stop. We always talk about recipes, what you do, who is doing what, why you doing that, things like that."

In Toronto, she's tried to carry on the tradition with her children and grandchildren (Walsh and his wife have three kids; the oldest, Noah, just graduated high school and will be working in the kitchen at Leña when it opens). "Sometimes it's hard, but every Sunday, I'm in the kitchen, and we all eat together," Arevalo says.

One of Leña's signature dishes is one Walsh first tasted in Arevalo's kitchen. "It's a beautiful story, and it was one of the first [dishes from Elena] that really slapped me across the face," says Walsh.

The Arevalo family calls the dish Pollo Doña Aurora, and Arevalo launches into the story of when she first savoured it as she slips the empanadas into the oven and then begins seasoning some chicken breasts with saffron, bay leaves and lemon.

"The day when we were leaving for Canada, my aunt Aurora invited us around and they did this chicken dish, so I asked her what was in it because we love it," she says. "Since then it's been in the family," she says.

"It's fantastic," says Walsh, "and it was really one of the first dishes, eating at their house way back when – and I was a young cook, a know-it-all – that slapped me on the side of the head. It's an odd combo of spices. Laurel, saffron and lemon – I would never have put those things together back then, but it just kind of woke me up."

Later, as Arevalo and Walsh serve up the Pollo Doña Aurora, its savoury medley of flavours infused into the tender white meat, the chef explains that while Leña is an Anthony Walsh production, it is more so a tribute to "mothers, grandmothers, aunts – a matriarchal homage."

"I never thought what I do would have such an impact on him," Arevalo says.