Heat oil in a skillet over medium-high heat for 30 seconds. Add onions and bell peppers; cook, stirring occasionally, for 3 minutes until tender.
Add garlic and ground beef. Cook for 5 minutes, breaking up the meat as it cooks, until browned and no longer pink.
Stir in tomato sauce, diced tomatoes, and water. Bring to a simmer, then reduce heat to low and simmer for 5 minutes, stirring occasionally.
Add pasta, cover, and simmer on low heat for 15 minutes until the pasta is tender.
Transfer to a bowl and enjoy hot.
