Preheat oven to 375°F.
Cook macaroni 3 minutes less than package directions. Drain. Set aside.
Heat oil in a Dutch oven over medium-high heat. Add beef and cook, breaking into pieces, until browned, about 6 minutes. Drain grease, return meat to pan. Stir in bell pepper, onion, carrots, garlic, salt, and pepper and cook, stirring often, until peppers are tender, about 5 minutes.
Stir in tomato sauce, Worcestershire sauce, brown sugar, dry mustard, and 1 ½ cups water; stir to combine, bring to a simmer, reduce heat to medium-low and cook, stirring occasionally, until thickened, about 5 minutes.
Add pasta to meat mixture, and stir to combine. Pour into a lightly greased 7- x 11-inch casserole dish. Top evenly with cheese. Sprinkle with bread pieces and bake at 375°F 20 minutes or until cheese is bubbly and lightly golden brown. Garnish with fresh parsley leaves.
