In a large skillet, heat olive oil over medium-high heat. Add the onions and garlic and sauté about 3 minutes or until garlic is fragrant.
Add red bell pepper and cook another 3 minutes.
Add ground beef to the skillet and cook until browned. Should take about 5-7 minutes.
Add remaining ingredients to the skillet and mix well. Cover the skillet and cook about 7 minutes or until the squash is tender, stirring occasionally.
