St. Leonard’s will open on Leonard Street in Shoreditch this May, and will be the second shared venture for the pair.
The menu will be inspired in part by South West France, following a series of dinners Clarke developed at his solo restaurant, Bastien. Other influences will be drawn from the rustic style of cooking both chefs learned from their grandmothers.
A regularly-changing menu will include a raw bar of fish, vegetables and crustaceans; and larger plates such as whole roast duck and ribs of veal, cooked over a log-fired hearth.
Much of the vegetable produce will come from Pound Farm in West Sussex, where the duo have been developing the menu.
The 70-cover restaurant will feature an open kitchen based around the log-fired hearth, and an adjacent ice bar.
A 50-cover bar will serve snacks, charcuterie and shellfish, alongside a 200-strong wine list; a cocktail menu; and a cognac and Armagnac-focused spirit list.
A 12-cover private dining room will be available for private hire and for catered daytime meetings.
Jackson is currently chef patron of Brunswick House and executive chef for the Chess Club in Mayfair.
Andrew Clarke joined Brunswick House as chef director at the beginning of 2016, following a series of stints at high-profile kitchens including Salt Yard, The Square, St. John, Anchor & Hope and The Swan in West Malling.
Clarke is also co-owner of Clapton neighbourhood biker café Jim’s Café, alongside award-winning bartender Tony Congliaro and The Black Skulls.
Since assuming his role at the restaurant, Brunswick House has received consistently positive reviews from the likes of Fay Maschler, Jay Rayner and the late AA Gill.