I serve with buttery mash and greens but just as good with a salad and bread to mop up the juices. You can also change the herbs and use tarragon instead of sage if you prefer.
You can add a few tablespoons of crème fraîche or cream at the end of the cooking time to make it more creamy. Take out the chicken let it rest, add the creme fraiche or cream, return to the heat and allow to thicken. Carve chicken and spoon the sauce over.
I have also added chantey carrots to the the stew before it goes in the oven having fried them off for a couple of minutes with the onions. This is also very good.
Recipe is from Spanish Recipes From San Sebastián And Beyond by José Pizarro