Remove the kernels from the Corn (6 ear). Reserve in a mixing bowl.
Add the corn cobs to a large saucepan along with the Sweet Onion (1) and Sea Salt (1 tablespoon). Cover with 12 cups of Water (12 cup) and bring to a boil. Turn the heat down to medium-low and gently simmer for 90 minutes. Discard the cobs and onion solids.
Add the Heirloom Tomato (4), corn kernels, Fresh Basil Leaf (1/2 cup) and Butter (2 tablespoon) to the corn broth. Simmer until the tomatoes have softened but the corn is still al dente, about 5 minutes.
Remove from the heat and taste for seasoning. Add more salt if necessary.
Ladle the soup into bowls and garnish with a drizzle of Olive Oil (1 tablespoon), and two tablespoons of Parmesan Cheese (1/2 cup) per bowl.