Pie with mushrooms and potatoes

The idea of this cake shared with me Irina (on the forum - Watercolor). Ira, thank you very much!
This cake can be made with different fillings - meat, fish, vegetables.
Ingredients

dough:
- 100ml milk
- 7-10 g dry yeast (or 20 g of fresh)
- 0.5 tsp sugar
- 1 egg
- 1 tbsp vegetable oil
- 250 g flour
- salt
Filling:
- 300 grams of mushrooms
- 400 g potatoes
- 150 g onion
- 150 grams of cheese (or semi-solid)
- sour cream (or mayonnaise)
Preparation
In a warm (not hot!) Milk add sugar and yeast.
In a warm place.
After about 15 minutes Opara should rise.
Whip the egg with salt.
Add vegetable oil and mix.
Add the approaching yeast mix.
Add the flour, knead not very stiff dough.
A bowl with the dough cover with a towel or tighten the film in a warm place.
I pour in a cup of warm water and put it in a bowl.
After about 30 minutes the dough should rise.
Onions cut into strips.
Mushrooms cut into thin slices.
Potatoes (raw) cut into very thin slices.
Cheese grate.
Form (I have a diameter of 26 cm and a height of 4) slightly oiled or lay a baking paper.
Roll out the dough about 3 mm thick. Put in a form so that there are bumpers.
The dough is a little grease cream.
Put the mushrooms, a little salt and pepper.
Mushrooms put onions.
Onion put potatoes, a little salt.
Lubricate the sour cream.
Sprinkle with cheese.
Put in a preheated 180 degree oven and bake for 30-35 minutes.
When serving, you can sprinkle with herbs and serve with sour cream.
Bon Appetite!