Start by making the sauce. In a small saucepan, combine the wine, vinegar or vermouth and the shallots. Bring to the boil and reduce by half. Add the cream and bring back to the boil. Whisk in the mustard. Turn the heat to low and slowly add the cold butter one cube at a time, whisking constantly, until all the butter has been incorporated.
Strain the sauce into a small bowl, cover with cling film and place over a gently simmering pan of water (not touching the water) until ready to serve.
Preheat the oven to gas 4, 180°C, fan 170°C.
Heat the olive oil in a frying pan. Rub the chicken breasts with the peeled garlic clove and season with salt and pepper. Sear the chicken breasts well on the skin side for 1 minute and then for 30 seconds on the flesh side.
Turn them back on to their skin sides and place the pan in the preheated oven for 8-10 minutes, or until cooked through and the juices from the breast run clear.
While the chicken is in the oven, prepare the petits pois. Melt the butter in a large pan over low-to-moderate heat and cook the onion and pancetta until the onion is really soft. Add the lettuce and cook for 2 minutes. Add the stock and thyme, and bring to a simmer, then tip in the peas and cook for 5 minutes, until cooked through. Season to taste.
Finish the sauce by adding the chopped tarragon, lemon juice and salt to taste.
Serve the chicken breasts with the petits pois and the sauce passed in a warmed jug.
If the butter should separate out of the sauce, melt a little butter in a clean pan over a gentle heat and slowly add the separated sauce, stirring constantly. The sauce should then become smooth again
Recipe by Matt Dawson host of The Real Food Family Cook Off
For top tips on protecting you and your family when preparing raw meat and poultry, visit Food Safety in the Home and view the full Food safety at home video.