Preheat oven to 160C
Heat oil and butter in a large casserole or ovenproof frying pan over medium-high heat. Add chicken skin-side down and cook, turning once until golden about 6-8 minutes. You will need to do this in batches, placing each batch into a large casserole or roasting pan.
When your final batch is golden on both sides add the garlic to the pan and stir to combine. Add wine reduce slightly then add the stock. Pour over chicken.
Transfer to the pre-heated oven and roast until chicken is cooked through and the juices run clear, about 20-25 minutes. Transfer chicken to a plate and keep warm.
Whisk cream and mustard into pan juices and simmer over medium-high heat until reduced by a third about 6-8 minutes. Add sage, lemon zest and juice and season to taste. Return chicken to pan and keep warm until ready to serve.
75 ml olive oil
60g butter, coarsely chopped
300ml dry white wine
2kg Fermier bone in, skin on, chicken thighs this should give 12 thighs in total
4 Garlic cloves, peeled and crushed
8g Simon Gault chicken stock concentrate mixed with 150ml water
60g Dijon mustard
1 packet fresh sage, picked
1 Lemon, juice and zest