In a large saucepan, fry onion in olive oil and until tender. Add garlic and fry till fragrant.
Add canned tomatoes, stock (can use stock to "wash out" any juice still in the cans to add into the soup), quartered tomatoes, half the sugar, good dash of salt and pepper.
Bring to boil, then reduce to a simmer, partially covered for about 20-25 minutes.
In about 10 minutes, think about starting to cook your rice according to packet directions.
After 20 minutes of cooking, take your soup saucepan off the heat to cool a little, and puree. Stick blenders are good for this but be warned the tomato may stain a little. If too thick, add in reserved chicken stock.
Put back on low heat and taste. If not "tomatoe-y" enough, add in the tomato paste and stir. So much of this has to do with the quality of tomatoes. Add in a little sugar now if you think it needs it. Add in salt and pepper if you wish, and the herbs of your choosing. Cook for a couple of minutes.
Add cooked rice to bottom of bowls and spoon over soup. Top with a generous dollop of sour cream (to be stirred in). Garnish as desired.