Making the announcement on social media site Twitter, the chef said of Abbott: “I’ve never worked with such a calm and collected chef.”
Abbott has been working at the two-Michelin starred restaurant for the past eight years, having joined as chef de partie in 2010. He was made head chef four years later.
He has previously worked for chefs including Andrew Fairlie at Gleneagles and Paul Kitching at restaurant 21212.
Abbott, who hails from County Antrim in Northern Ireland, cooked in the finals of the 2016 edition of Great British Menu having scored the highest-ever marks on the heats of the BBC2 cooking show at the time.
In October, Midsummer House retained its two-star rating in the Michelin Guide for Great Britain and Ireland, the fourteenth consecutive year it has held the rating.
Speaking to Restaurant magazine earlier this year, Clifford said that he was still pushing for a third Michelin star. The restaurant celebrated its 20th birthday earlier this year and was given a £400,000 refurb both front and back of house.
“I still want them [three Michelin stars], what chef doesn’t?,” he said. “I’ve still got it in me, and I’m still investing in the restaurant.”
In his tweet, Clifford said that Abbott would help ‘take us to the new level’.