Heat olive oil in a large pan over medium-high heat. Add the ground beef and cook until browned and crumbled. Sprinkle in part of the Cajun seasoning and cook briefly.
Add the onion, bell peppers, and garlic. Cook until the vegetables soften and become fragrant.
Add the onion, bell peppers, and garlic. Cook until the vegetables soften and become fragrant.
Break the spaghetti in half so it fits neatly in the pot, then add it along with the broth. Make sure the pasta is submerged.
Bring the pot to a boil. Stir often, until the spaghetti is al dente and the liquid thickens into a glossy sauce.
Stir in the remaining Cajun seasoning and black pepper. Add salt only if needed. Top with sliced green onions