Preheat the oven to 200°C.
Combine the brown sugar, vinegar, Worcestershire sauce and tomato sauce in a small bowl. Heat the extra virgin olive oil in a large skillet or Dutch oven over medium-high heat. Add the beef and cook until well browned. Season with salt and lots of pepper. Add the garlic, bell peppers and onions and cook, stirring, for 5 minutes. Pour the tomato mixture over the beef, add the beef broth and stir until well combined. Simmer until thickened, 5 to 10 minutes.
Meanwhile, cook the macaroni in a large pot of salted boiling water until not quite tender, about 5 minutes. Drain and add to the sauce. Pour the mixture into a casserole dish and top with the cheese.
Bake until the casserole is bubbling and the top is browned. Top with the pickles and serve from the dish.
Cook's Note: The unbaked casserole can be covered and refrigerated for a make-ahead meal. Bring to room temperature and bake as directed before serving.
Recipe courtesy of Rachael Ray