Start by preheating the oven to 400 degrees Fahrenheit. Put your tomatoes on a greased baking pan.
Mix together garlic and 1/4 cup of oil and then you can coat the tomatoes in this mixture. Bake for 20 minutes, stirring tomatoes every once in a while. They should cook until they have softened. Once they are done cooking, you can get rid of the skins.
Separately, take the remaining oil and sauté your onion in it. Add salt, water, and tomatoes. Cook in a pan on medium heat until it starts to boil. Once it boils, you can lower the heat and cover the pan, allowing it to simmer for 30 minutes.
Use a blender to process the soup, and you will likely have to do this in batches. Use the blender to make the soup smooth, and then stir the cream into the soup and heat thoroughly.