In a heavy pot over medium heat, heat olive oil and saute onions until a bit translucent, about 5 minutes. Then add tomato paste, garlic and stir for a couple of minutes.
Add tomatoes, jalapeno, thyme, salt & pepper and cook until tomatoes are soft and tender, about 10 minutes.
Add the chicken stock and stir. Taste mixture and adjust salt & pepper to taste if needed. Let mixture come to a boil and then let simmer for 10 min.
Remove sprigs of thyme from pot and discard. Carefully fill blender with mixture, about half way full. Cover and blend until tomato soup is smooth. Repeat this step until you've blended all the tomatoes. If you have an inversion blender, blend the tomatoes in pot until you've reached desired consistency.
If you used a blender, transfer the soup into original pot and stir in cream slowly and simmer for a few minutes. Serve soup in bowl and top with croutons.