This dish should be prepared in winter when root vegetables are at their best. What is important to the success of this recipe is the cut of the vegetables. The shape of the cuts can be simple, such as 1/2-inch slices, batons or they can be cut into triangular shapes. All the pieces should be cut the same size so they will cook in the same amount of time. I like using equal parts of different root vegetables. You can use whatever variety of root vegetables you'd like, such as potatoes, carrots, turnips, rutabagas or celery roots, for a total of about 5 cups of cut vegetables. A rosemary sprig or other herb tossed in with the butter will add a light herbal flavour and aroma to the dish. It is easier to peel turnips, rutabaga, and celery root with a paring knife than with a vegetable peeler, which doesn't reach deep enough to remove the tough layer under the skin.
Try this dish with roast chicken or braised meats.
Heat the oil in a Copper-Core Cassoulet over low heat.
Raise the heat to medium, then add the vegetables.
Cook, stirring frequently, for 10 to 12 minutes, or until the vegetables are tender and evenly caramelised.
Season with salt to taste, stir in the butter and, if desired, the herb sprig just before serving.