3 sweet leek gratin Recipes

sweet italian sausages, casings removed, canned low-salt chicken broth, dry white wine, apricot nectar, butter, sliced leeks (white and pale green parts only; about 4 leeks), tan-skinned sweet potatoes, peeled, thinly sliced, chopped fresh thyme or 1 tbsp dried, freshly grated parmesan cheese (about 2 oz)

unsalted butter, leek, white and tender green, thinly sliced, homemade dry bread crumbs, freshly grated gruyere cheese, jerusalem artichokes , thinly sliced crosswise, salt and freshly ground pepper, sweet potato (about 1/2 lb), peeled and thinly sliced crosswise, heavy cream