Melt the butter in your large stockpot over medium heat. Add the diced onions and cook for five minutes. They should be very soft and look quite clear.

Stir in the minced garlic and the dry spices now. Cook for just one minute so the garlic smells sweet. Do not let the garlic turn dark or bitter.

Pour in the whole tomatoes and the savory chicken broth. Add the sugar to balance the very tart tomato juice. Stir everything together with your wooden spoon.

Bring the liquid to a light boil and then lower. Let it simmer for twenty minutes on the stove. This helps all the flavors blend into one deep taste.

Use your immersion blender inside the hot stockpot. Blend until you see no chunks of onion or tomato. The soup should look very thick and bright red.

Stir in the heavy cream and the fresh basil leaves. Let it heat through for two more minutes total time. Serve it hot with a sprinkle of black pepper.