Prepare the sauce as directed above. Substitute a couple of large carrots and/or parsnips for a few potatoes. Cut the carrots in 1½-inch (4-cm) slices. Halve or quarter 2 to 3 turnips, depending on their size—the pieces should all be consistent in size with the potatoes. If available, add 1 to 2 quinces. Halve each quince horizontally and then quarter and core them (but keep the skin). I find that the firm-fleshed, tart fruit beautifully complements the sweet medley of root vegetables. Arrange the vegetables and quince in the pan, cover with the sauce, toss and proceed as directed.