Heat your olive oil in a large pot. Add the onions and sauté for a minute or two. Stir in the garlic for 15 seconds. Mix in the tomato paste until its incorporated. Toss in the potato pieces and cook for 2 minutes. Season with salt and pepper to taste.
Mix the sugar into your grated tomatoes.
Add the green beans, tomato mixture and 1 cup hot water to the pot. Gently mix everything, stirring from the bottom the pan, upwards. Bring to a boil, lower the heat to a simmer and cover your pot. Uncover and stir occasionally for about 20 minutes. Cook uncovered for another 15 minutes or until sauce is creamyish your green beans are fork tender and cooked to your preference. You may need to add the 1/2 cup warm water if liquids in the pot evaporate and the beans aren't cooked yet.
Add the fresh parsley and toss.
Notes
Serve with fresh bread and feta cheese.Discard the skins of the tomatoes.