On a medium heat, in a larger pot put on the oil, onion, and carrots.

When the onions become almost translucent, put in the mushrooms.

Once the onions are translucent, take off the pot from the fire, and wait until the oil is not boiling any more.

Add the salt, pepper, bay leaf and sweet red pepper, mix it well.

Then add the potatoes, mix well again.

Add enough water to cover the potatoes (and a bit more).

Put back the pot on the fire, and cook it until the potatoes become soft.

Add the rice, make the roux using the sour cream and flour, and add it as well.

Cook at most 10 more minutes, until the rice is ready.