Cook spaghetti noodles in salted water and set aside.
Heat olive oil in skillet and cook onion and garlic until onion softens.
Add ground beef or turkey and brown for 5-7 minutes, breaking it up.
Mix in taco seasoning.
Add ROTEL tomatoes and simmer for 5 minutes.
Drain spaghetti noodles and add to taco meat mixture.
Stir everything together.
Transfer to a serving dish, sprinkle cheese on top, and allow it to melt.
Add optional toppings like cilantro and sour cream if desired.