Best scalloped potatoes ever

Ingredients

potatoes 2.2 lbs
milk 1L
butter 100g
onion 1 bulb
ground black pepper
spices
salt

Preparation:

Step 1 Wash, peel and slice potato tubers thoroughly. Dice the onions. Mix both ingredients, add salt and ground pepper, any dry spices. Put the mass into a casserole dish as a layer of five centimeters, pour milk over it. On top of the casserole put slices of butter.
Step 2 Bake at 200 degrees for 15 minutes, then turn down to 150 degrees and bake for another 40 minutes. Another option: make the temperature to a minimum and leave the dish in the oven for 2-3 hours. When serving, sprinkle the baked potatoes in milk with green onions.

Note:

To prepare the dish, it is better to take fresh country milk, it should not curdle. Potatoes are better to take a medium density, it should not fall apart. The casserole can be prepared in portion pots. If desired, you can add onions and roasted pork to the mass.