Fried strings with onions

So we start cooking:

Wash the mushrooms thoroughly, soak for 15 minutes, then wash again. Usually there is a lot of sand in such mushrooms.
Fill the lines with boiling water, bring to a boil, drain the water and rinse.
Pour hot salted water again, cook until the mushrooms are boiled every five times.
Peel and chop the onion, fry it in vegetable oil until slightly golden brown.
Add the mushrooms and fry for 10-15 minutes on medium heat under the lid, stirring from time to time.
We serve fried mushrooms with potatoes. Add salt.
Bon appetit!