2 quarts homemade chicken stock (read my method here)
1/2 bunch fresh basil (approx 1 cup loosely packed leaves)
1/2 cup half & half
salt and pepper to taste
Parmesan cheese, to taste
In a large 5-6 quart capacity pot, melt butter over medium heat and add onions; cook until translucent, approximately 3-5 minutes.
Add garlic and cook for 3-4 minutes, until aromatic.
Add tomatoes and stock and bring to a boil. Reduce heat to a simmer, cover and cook for 20 minutes.
Add basil, tearing the leaves and stems (if using) as you go. Puree with an immersion blender until smooth. Turn off the heat and add cream while stirring. Serve with salt, pepper and Parmesan cheese to taste.