Melt the butter in a soup pot and add the chopped onions and celery. Cook for about five minutes, or until the vegetables are soft and wilted. Add the basil and cloves and cook another minute or two until fragrant, then add the flour. Continue cooking for another two minutes, stirring, and then add the tomatoes, followed by the baking soda and the stock.

Lower the heat and simmer for ten minutes or so. Remove the pot from the heat and carefully puree the soup in batches in a blender, or using a stick blender in the pot, off the heat. Return the soup to the heat and add the milk, stirring to blend. Add more milk or stock if the soup seems too thick. Add a little tomato paste if it needs more tomato flavor. Add some freshly ground black pepper and salt, to taste. Serve hot with optional garnishes, listed below.

Absolutely at its best when serves with grilled cheese sandwiches.