Heat olive oil in casserole dish, add mushrooms and cook while stirring until tender and starting to turn golden brown.

Season chicken and sear on all sides until golden brown

Add garlic and onions to the dish and continue cooking for a couple of minutes until they turn translucent.

Add thyme, 3 sprigs of tarragon and wine and bring to a summer.

Leave to bubble until the wine has evaporated then sprinkle over the flour and stir to combine.

Pour in the chicken stock and bring to the boil.

Add the seared chicken and simmer reducing the liquid by about a third.

Pour in the cream and stir through the sauce. Arrange the chicken in a single layer so each piece is covered by the sauce. Check seasoning and simmer for around 15 minutes

Turn chicken pieces over and add leaks and peas. Stir into the sauce and simmer for around 10 minutes ensuring chicken is cooked through.

Stir in a little chopped tarragon and leave to rest to allow flavours to combine.