Heat medium saucepan over med-low heat and add butter. Add in shallots and garlic, cooking until soft and slightly golden stirring occasionally, about 8-10 minutes. Stiir in the tomato paste and cook for another 5 minutes. Add in the tomatoes, sherry, chicken stock, brown sugar, basil, salt and pepper, then bring the mixture to a boil. Reduce to simmer and cook 20 minutes.
Transfer the soup to a high-powered blender and carefully blend until pureed. Transfer back to the pot over low heat. Right before servin, stir in the heavy creamm. Taste and salt and pepper if needed. to serve, drizzle the soup with extra cream and garnish with chives.
For Grilled Cheese Sticks: Spread the outsides of the bread with the softened butter. Heat a large griddle or skillet over medium-low heat. Toss the fontina and gruyere and parm together, then fill the sandwiches with cheese, topping the bread with a slice buttered-side up. Cook the sandwiches until golden on both sides, about 5-6 minutes per side, and the cheese is melted. Let them cool slightly, then slice into "sticks" with serrated knife. Serve with the soup shooters.