Baked Potato Salad

3 medium-sized potatoes (preferably Idaho)
water
1 1/3 tsp. salt
2 Tbls. salad oil
1/2 cup onion, chopped
1 tsp. dry mustard
1/4 tsp. celery seed
2 Tbls. apple-cider vinegar
1/2 cup green pepper, diced
1/4 cup carrot, shredded

Put potatoes in a large saucepan with 1-inch cold water and 1 tsp. salt; bring to a boil. Cover, reduce heat and simmer 25 minutes, until potatoes are tender; drain and cool. Peel potatoes and slice 1/4-inch thick; set aside. Heat oil in a medium-size skillet; saute onion until soft. Stir in flour, mustard, celery seed and remaining 1/3 teaspoon salt. Gradually add 1/2 cup water and vinegar; cook over low heat, stirring constantly, until mixture boils and thickens. Combine potatoes, green pepper and carrots in a bowl; add sauce, mixing well. Spoon half the mixture into a shallow 8x8-inch baking dish; sprinkle with 1/2 cup cheese. Cover with remaining potato mixture and cheese. Bake, uncovered, in preheated 350 degree oven 15 to 20 minutes, or until cheese is melted and vegetables are hot. Enjoy!