One-Pot Saucy Pasta

Heat a large skillet over medium-high heat. Cook and stir beef and onion in the hot skillet until browned and crumbly, 5 to 7 minutes. Drain and discard grease.

Add water, pasta, and spaghetti sauce to the skillet and bring to a boil, about 5 minutes. Cover and reduce heat to low. Simmer, stirring occasionally, for 15 minutes.

Add bell peppers and mushrooms to the skillet and cook for 5 minutes.

Sprinkle with mozzarella cheese and serve.