How we do it at home:

• Chautee the green beans with some oil and grated onion.
• Add the carrots (in small slices) and potatoes (in cubes) and let them cook a bit.
• Don't forget to mix constantly, as you don't want them to stick in the pot.
• Add the tomato sauce, salt and pepper.
• Add water and let it boil.
• My mum used to grate some zucchinis, it made the texture different, thicker.