Cook and crumble the ground beef in a large pot over medium-high heat for 2 minutes. Add onion and cook 5 minutes, until beef is browned and onion softened; drain grease.
Add bell pepper and garlic; cook about 4 minutes. Stir in chili seasoning and tomato paste; cook 1 minute.
Add tomato sauce, undrained diced tomatoes, and broth. Bring to a boil, reduce to a gentle bubble, partially cover, and simmer while making the macaroni and cheese. Add kidney beans during the final 10 minutes.
Heat oven to 400°F. Boil salted water, cook macaroni just to al dente according to package directions, and drain.
Melt butter in a large pot over medium heat. Whisk in flour for 2 minutes. Add cream and milk gradually while stirring.
Bring sauce to a boil, reduce to a simmer, stir in hot sauce, mustard powder, onion powder, salt, and pepper, then reduce heat to low.
Gradually add shredded cheddar, stirring until smooth. Add drained macaroni and combine.
Gently fold chili into the macaroni and cheese. Top with remaining cheddar and bake uncovered for 5 minutes, until melted. Garnish with parsley if desired.