Potato, carrot and onion--not a revolutionary idea. One of my favorite veggie combos of all time, try it this way for a change of pace-
6 medium potatoes
1 medium onion
6 medium carrots
1 teaspoon salt, divided
2 tablespoons butter, divided
freshly ground pepper
1 1/2 cups half and half
Slice potatoes thinly and divide into 5 parts. Peel and slice carrots thinly, divide into 4 parts. Peel and slice onion thinly, divide into 4 parts. Butter a oven proof serving dish. Place one portion of potato in a layer across the bottom of the baking dish, top with one portion of the onions and one of the carrots. Sprinkle 1/4 teaspoon salt and some fresh pepper over the top and dot with about 1/2 tablespoon butter; then layer another portion of potatoes, onions and carrots topped with salt, pepper and butter. Repeat twice more then finish with a layer of potatoes. Pour half and half over top slowly and dot with any remaining butter. Cover tightly and cook in a 300 degree oven for 2 hours or more, (depending on how deep the dish is,) or until the veggies are soft and the liquid is absorbed.
Hints: If I use my dutch oven that is quite deep, I bake this about 3 hours. If I use a glass 9 x 13 inch pan, it takes less time. I do not peel the potatoes but I do the carrots. This is a good go to side because my pantry usually has all these ingredients. I use a mandolin to do the slicing but a food processor would be slick to use.
Everybody that has ever had this dish has really enjoyed it. The flavor profile is universally appealing it seems. Not every dish can claim that, nor would we want them to but, it is good to have a few of these in your repertoire.