Add oil to the pot and heat over medium heat. When the oil gets hot, add flour and make roux.

Add tomato paste to the roux and stir it for a minute so it can combine together roux and tomato paste. Add canned diced tomato and water. Whisk the mixture together until smooth. Add dry basil, dry oregano, dry thyme, parsley flakes, and salt.

Place a lid on the pot and allow it to come up to a simmer. Once simmering, remove the lid, turn the heat down to medium-low, and let it simmer, stirring occasionally, for 20 minutes.

After simmering for 20 minutes, taste the soup and add salt to taste, or sugar if the soup is too acidic. Serve hot.