In a large saucepan, heat butter & oil over med high heat. Add onions, shallots,garlic,thyme and bay leaf. Season with salt & pepper. Cook until onion is wilted. Add tomatoes, paste & basil sprig. Let simmer for 10 minutes. In a small bowl add flour and small amount of stock and simmer for 40-50 minutes,stirring frequently to make certain soup does not stick to the bottom of the pan. Remove thyme,bay leaf,and basil.

Put the soup through a food mill or puree it. Add sugar,butter.adjust seasoning,sprinkle with fresh dill.