Preheat the oven to 275 degrees F.
Place a large roasting pan over 2 burners set to medium heat. Add the butter, garlic and onions and sweat for 6 to 7 minutes. Add the tomato paste and cook for 2 to 3 minutes more. Add the tomato sauce and chicken stock and bring to a simmer. Cover with foil and transfer the pan to the oven for 5 hours, stirring every 30 minutes. (Baking in the oven ensures the sauce cooks down without burning.)
Transfer the sauce to a blender along with the basil, Parmesan and sugar, and blend well. Season with salt and pepper. Toss the cooked pasta with the sauce. Serve in shallow bowls, garnished with Parmesan.
Recipe courtesy of Jimmy John Liautaud