@msolga,
Well, my ex sent me the Paul Bocuse cookbook (which he ended up with since he bought it) because I was asking about the potato au gratin recipe - by far my favorite/all time. And.. it's easy - well, fairly easy.
2 - 1/4 lbs potatoes (I use waxy/reds), 1 kg
2 - 1/2 cups of milk, 60 cl
nutmeg
salt, pepper
1 clove garlic, peeled and split lengthwise
1 - 2/3 cups grated swiss cheese, 125 g
3 tablespoons heavy cream, 5 cl
2 tablespoons butter, broken into small pieces, 30 g
Preheat oven to 400 degrees (200 C)
Peel the potatoes and wash quickly in cold running water, then wipe dry.
Cut them into slices about 1/4 inch thick and reserve, (5 mm) - I use a mandoline.
Bring the milk to a boil in a large saucepan, add the potatoes, a little nutmeg, and salt and pepper generously. Shake the pan gently to make the potatoes settle into the milk. (They should be barely covered by the milk; if not, add a little warm water.) Lower the heat and simmer, uncovered, over very low heat for 20 to 25 minutes, or until tender.
Rub a baking dish (preferably porcelain or earthenware) with the garlic.
When the potatoes are done (simmering), lift some out of the milk with a slotted spoon and cover the bottom of the baking dish. Sprinkle with a little grated cheese, add another layer of potatoes, sprinkle with cheese, and continue filling the dish, layer by layer, ending with cheese.
Measure the milk remaining from cooking the potatoes; there should be about 2/3 cup (15 cl) left. If there is more than that, boil to reduce to this amount, then pour it over the potatoes. Spoon in the cream, dot the surface with butter, then place the dish in the oven and bake for 20 minutes, or until the surface is golden brown.
Osso - I use a mandoline for thin potato slices, and flip the potatoes right into warm milk as I'm slicing them. I use more garlic in the casserole, but I'm a garlic nut.
One can probably add some al dente veggies in that layering, but I've never tried that.. or wanted to, it's so good.