An Acclaimed Puerto Rican Chef Will Run a New Massive Austin Restaurant With Tostones and Caviar

A massive new restaurant is coming to downtown Austin in 2023, taking over what had been the sprawling Boiler Nine Bar + Grill. Ember Kitchen & Subterra Agave Bar will open at 800 West Cesar Chavez Street, Suite PP110 in the Seaholm Power Plant development starting in January 2023.

Executive chef María Mercedes Grubb, a renowned Puerto Rican chef from San Juan, is leading Ember’s kitchen and making her Texas debut. She’s excited about using her cooking experiences and expertise to create a live-fire menu, especially within the Puerto Rican, Dominican, and Caribbean cuisines, as she tells Eater. “I want to figure out as many things that we can impart flavor with fire,” she says; she and the team will be using the restaurant’s huge Josper oven and grill, which uses both charcoal and wood.

For Ember, this means dishes like live-fire cooked meats, seafood, and vegetables paired with sauces, like the wagyu skirt steak with chimichurri or the roasted squash with salsa macha made with Marcona almonds. There’s also a large packed seafood tower with charcoal-cooked items.

Other more fun dishes include caviar served with tostones (twice-fried plantain slices); oysters dressed with a charred passionfruit mignonette; large prawns served with hibiscus and garlic; a Caesar salad with chicharrones instead of breadcrumbs; and an oxtail stew with guajillo polenta.

“It’s very important to me that umami comes through because I think that’s the ultimate thing about Caribbean food,” Grubb says, “pushing the envelope and not being scared of flavor.” She’s also making it a point of using Puerto Rican ingredients like gandules (pigeon peas) and achiote.

James Beard Foundation

Ember Kitchen & Subterra Agave Bar

Ember Kitchen & Subterra Agave Bar

Ember’s key operating partner is the Austin-based hospitality financial startup InKind (which it spells inKind). The company is using the restaurant to try out programs, technologies, marketing actions, and the such for potential use by its clients. The company allows people to pre-purchase dining credits through its app for participating restaurants.

Grubb, who grew up cooking and learned from her Dominican parents and grandmother in San Juan, moved to New York to study at the French Culinary Institute. After that, she worked at fine dining restaurants: Michelin-starred restaurant the Modern when chef Gabriel Kruether was there, Spanish restaurant Bar Basque. Italian restaurant Maialino, and Gramercy Tavern.

When Grubb was done in New York, she moved back to Puerto Rico to be with her family in 2013. That’s also when she opened the restaurant and cocktail bar Gallo Negro, for which she became a James Beard Awards semifinalist in 2019. She closed that restaurant later that year because the island was still struggling after earthquakes and Hurricane Maria in 2017. She took some time off and then opened two new restaurants in San Juan in early 2022: gastropub Taberna Medalla and hotel restaurant Suma. When her roles were ending at those businesses, she got a call from InKind asking if she’d be interested in the Austin project.

Ember Kitchen & Subterra Agave Bar

Similar to its predecessor, the new downtown restaurant will include three distinct areas: the ground-floor restaurant called Ember that seats 78 people; the underground bar named Subterra Agave Bar; and the unnamed rooftop bar (which will open later next year). The entire space is being softened up from Boiler’s industrial look, including more soft surfaces, a living green wall, and bright murals.

Within Subterra, leading the cocktail menu is Chris San Andres. Per the name, expect cocktails making use of agave spirits. The Od Dashioned uses whisky with the Central American herb epazote and agave; the sour with bacanora and cachaca; the martini with blanco tequila, vermouth, olives, and cardamom; and Mai Tai with charanda and mezcal.

Ember’s hours will be from 5 p.m. to 11 p.m. Wednesday through Sunday, and the bar will be open until 2 a.m. The restaurant is currently hiring for all positions.

Boiler Nine opened in 2016 by parent company La Corsha Hospitality, with a similar wood-fire menu and multi-area experiences. It closed in 2019 because the restaurant's ownership company Boiler Nine Partners Ltd. didn’t pay management fees, according to La Corsha.

Ember Kitchen & Subterra Agave Bar