In a saucepan over medium heat add in olive oil and onions. Cook unitl translucent.
Add in the tomatoes, broth, and seasonings. Stir until combined.
Continue to cook over medium low heat untl your soup is the temperature you enjoy.
If you are not a fan of the pieces of onions and want a smoother soup you can use an immersion blender or blender to puree them for a smoother soup.
Notes
You can use any type of tomato. However, you may need to puree your soup in a blender before serving. The crushed tomatoes give the soup a great consistency without needing to blend.