This is a recipe that I usually do with pork chops and its amazing. Although, as you may gather from the title this version has been adapted to use up leftovers. I recently posted this recipe to Nigella Lawson's Foodim and it became the #postoftheweek and had a lot of requests for the recipe so here it is.
Heat the butter and oil in a large heavy based pan, I use a shallow casserole, over a medium heat. Add the minced garlic along with the sliced mushrooms allowing to cook, without stirring, until brown on the first side before stirring the pan and cooking for a further 2 minutes.
Stir in the thyme and half of the chopped parsley, reserving the remaining for later. Pour in the vermouth, scrape at the bottom of the pan to remove any bits stuck to the bottom of the pan. Allow to bubble away for a further moment. Stir in the cream and wholegrain mustard.
Tear the roast chicken into bitesize pieces and add to the pan, once it begins to bubble again reduce the heat and allow to simmer for 5 minutes.
Meanwhile, cook the gnocchi in boiling salted water, as soon as the little dumplings float to the top they are cooked and can be transferred to the pan of creamy sauce. Stir together to amalgamate everything, season to taste with sea salt and blanket with the remaining chopped parsley. Serve immediately.