Brown the beef: Heat a large, deep skillet over medium-high. Add the ground beef and cook, breaking it up, until no longer pink and lightly browned, 5–6 minutes.
Drain excess fat if needed, leaving about 1 tablespoon in the pan.
Sauté aromatics: Add onion and bell pepper. Cook until softened, 3–4 minutes. Stir in garlic and cook 30 seconds until fragrant.
If the pan looks dry, add a splash of olive oil.
Season the base: Stir in salt, pepper, paprika, Italian seasoning, and red pepper flakes. Toast the spices for 30 seconds to wake up their flavor.
Add tomatoes and paste: Mix in crushed tomatoes and tomato paste until smooth. Let it bubble for 1 minute to concentrate.
Cook the pasta in the skillet: Pour in the beef broth and bring to a strong simmer.
Add the dry macaroni and stir well so it doesn’t stick. Reduce heat to medium, cover partially, and cook 9–11 minutes, stirring every couple of minutes. Add a splash more broth or water if it gets too thick before the pasta is tender.
Finish with cheese: When pasta is al dente and the sauce is thick and glossy, remove from heat.
Sprinkle cheese over the top and cover for 1–2 minutes to melt. Taste and adjust salt and pepper.
Garnish and serve: Sprinkle with parsley or green onions. Serve hot, straight from the skillet.