Slice the onion thinly, separate broccoli into small florets, and mince the garlic after removing its core.

Heat olive oil and garlic in a pan over low heat until fragrant. Add onion and sauté over medium heat until softened, then add beef and cook until its color changes.

Add canned tomatoes, water, salt, and pepper. Bring to a boil, then add spaghetti (broken in half). Cover and simmer on low heat for the pasta's package cooking time. Add broccoli 2 minutes before the end, stir, and cover again.