Vegetables in milk sauce

I learned to cook vegetables in milk sauce while working in kindergarten. This dish was often served for dinner. I adapted the recipe a little, added spices and removed the green peas. And it turned out just great. I serve vegetables in milk sauce in two versions: as a main dish with a fresh salad, and as a side dish with cutlets or fish.
Adjust servings in the full version
Cut the onion into half rings. We clean the carrots and cut them into cubes. Pour vegetable oil into a thick-bottomed pan (you can also cook with butter). Add the onion and fry a little. Add carrots. Mix.
Peel the potatoes and cut into cubes. We also put it in the pan. Mix everything. Add water to half the volume of vegetables. About a glass or a little less. Add some salt. Cover with a lid and leave to simmer.
Meanwhile, prepare the milk sauce. Pour milk and butter into a saucepan and place on the stove. Dissolve flour in half a glass of cold water. Gently add the flour mixture into the boiling milk, stirring all the time with a whisk. And cook until thickened. Add salt to taste.
While the sauce was being prepared, the potatoes had already become soft. The cabbage is still crunching a little, but it’s also almost ready. Pour milk sauce over vegetables. Add spices.