The steakhouse brand will open a restaurant in Brighton next month, followed by a site in Bristol this December.
The three new openings will bolster Flat Iron’s estate to 21 restaurants, with six of them outside the capital.
Flat Iron Bristol and Newcastle will serve a menu led by the brand’s signature steak, a cut sourced from the feather blade, as well as a rotating selection of dishes, including wagyu daily specials and burgers made using beef from the Flat Iron herd in Thirsk, Yorkshire.
Flat Iron’s expansion comes after its acquisition by private equity companies McWin and TriSpan last month.
The company also recently secured additional funding to support its expansion plans with a senior debt facility from bank OakNorth.