Using medium heat, heat a large pot on the stovetop. Add the oil and butter and allow the butter to melt.
Once the butter has melted add the onions. Cook the onions for a few minutes and then add the garlic. Cook the garlic and onions for another few minutes until soft.
Add the cream, water, sugar, oregano, and a few shakes of salt and pepper. You can easily leave out the cream and butter if you are dairy free.
Add the canned whole tomatoes to the soup and set the heat to high and bring it to a boil. After it comes to a boil set the heat back down to medium and allow it to simmer/cook for about 10 minutes. Break apart the whole tomatoes with a wooden spoon or silicone spoon. It is not absolutely necessary since we will be using the blender, but I always do it.
After the tomato soup has cooked, remove it from the heat. Ladle half of it into a blender and blend until smooth. Then pour the soup into a large bowl and blend the other half. Give the soup a taste and add more salt and pepper as desired.
Serve the soup with a grilled cheese sandwich, or slice of bread, or crackers, or however you like. Enjoy!