Pat the chicken dry with a paper towel and season with salt. Heat a Le Creuset 24cm Casserole over medium heat and drizzle with olive oil. Once hot, sear all the chicken pieces in batches until golden but not fully cooked. Add half the butter and baste the chicken in the melted foamy butter. Remove from the pan and set aside.

Add the remaining butter; once melted and foamy, sauté the shallots until soft. Add the garlic and sauté until fragrant. Remove the shallots and garlic from the pan. Add the mushrooms and sauté until golden.

Return the shallots and garlic to the pan and add the lemon zest and thyme. Deglaze the pan with the white wine or white wine vinegar. Reduce by a half. Season and add the stock and reduce by a third.

Add the sour cream to the casserole and stir well to incorporate. Season and add the seared chicken breasts into the sauce. Place the lid on the casserole and simmer over a very low heat until the chicken is cooked for 5-8 minutes. Serve with creamy mashed potatoes and chopped parsley or fresh thyme.