In a large skillet over medium heat, add your ground beef or turkey. Cook for about 5 to 7 minutes, stirring occasionally, until the meat is browned and no longer pink. Drain excess fat if necessary.

Stir in the taco seasoning and diced tomatoes, mixing well to coat the meat. Cook for an additional 2 minutes, allowing the flavors to meld.

Add the uncooked spaghetti to the skillet, spreading it out evenly. Pour in approximately 4 cups of water, ensuring the pasta is fully submerged. Bring to a boil, then reduce heat and cover. Simmer for 10 to 12 minutes, stirring occasionally.

Once cooked, remove the skillet from heat and gradually mix in the shredded cheddar cheese until fully melted and creamy.

Spoon the One-Pot Taco Spaghetti onto plates and garnish with toppings like sour cream, avocado, or fresh cilantro. Serve warm and enjoy.