Preheat oven to 375 degrees. In deep skillet, coat leeks and carrots with olive oil. Cover and simmer over low heat until soft. Add seasonings. Mix well. Layer a well-oiled 2 1/2-to 3-quaart casserole (with cover) with 1/3 of the potatoes, then 1/2 the seasoned vegetables. repeat and finish with last 1/3 of potatoes. Pour broth evenly into casserole. Cover and bake for 50 minutes covered at 375 degrees. Uncover and bake for another 20 minutes. Garnish with parsley and chives. Variation: Substitute carrots with zucchini if desired. Half of leek can be finely chopped yellow onions. Per serving: 290 calories. 7 grams fat.