The leading restaurateur, who was also maître d' of Dinner by Heston Blumenthal when it launched in 2011, was invited to join the project as a business partner and restaurant manager after meeting Gwen and Chris Wren and Shelby and Dunny Wanstrath in Lima restaurant last year.
The two couples have lived in London for a number of years and are now keen to open a venue where they can showcase their native cuisine.
“Having spent the last six years in central London we have been quite homesick for our native cuisine and noticed that most people in London don’t know what Southwest US food is all about," said Dunny Wanstrath, one of the co-owners of the Seymour Place venue.
The 70-cover Marylebone restaurant will have a warm, informal feel inspired by the American approach to running a restaurant.
Andrew Justice, who previously worked in fine dining for contract caterer BaxterStorey, will head up the kitchen and, together with the business's founders, has created a quarterly changing menu including dishes such as pork belly, buffalo fillet and Lockhart smoked chicken.
Gwen Wren, who has already tested the concept through an online gourmet takeaway service, is keen to marry Southwestern flavours with high quality ingredients. "While attending a culinary school in London I was inspired to elevate the food I grew up with in the Southwest US using high quality British ingredients.
"The Lockhart is dedicated to using Britain’s vast array of seasonal produce by partnering with local farms and suppliers. We are excited to be offering our concept of Southwest US cuisine to the London restaurant scene and thrilled to feature the best of what the UK has to offer," she added.
As well as Tex-Mex smoked and BBQ meats and vegetables, the team hope to offer 'undiscovered' dishes too. All the food will be freshly prepared and the corn tortillas, breads, pickles and jams will all be prepared by hand.
The Lockhart will also offer a cocktail selection influenced by the Southwest US using British produce. Award-winning Texan mixologist, Eddie 'Lucky' Campbell has created a number of the drinks.