Giouvarlakia with tomato sauce

Wash and peel the carrots and potatoes. Either julienne the carrots or cut into slices and quarter the potatoes. 

Place 2 to 3 cups of water in a pot, the oil, and boil the potatoes and carrots for about 10 minutes. 

Meanwhile prepare the giouvarlakia using the rest of the ingredients (ground beef, onion, rice, parsley and very little salt) and shape them into balls, adding as much water with your hand as is needed to make a soft mixture (take care that it is not runny). 

Carefully add the giouvarlakia to the pot with the potatoes and carrots, making sure they don't break. Boil for about 15 minutes over medium heat. 

Then, after 20 minutes, add the tomato passata, a little salt (make sure to taste it), a little pepper and shake the pot carefully so that the salt and pepper are evenly distributed. 

Let it cook for about 40 minutes (adding water from time to time if necessary) so that it absorbs its liquids and is left with just the sauce.