Heat a large pot over medium heat and add a splash of oil. Add the chopped onion and minced garlic. Sauté until the onion is translucent, about 3 to 4 minutes.

Add the ground turkey. Break it up with a spoon and cook until no longer pink and beginning to brown, about 5 to 7 minutes. Season lightly with salt and pepper.

Stir in the chopped bell pepper and the can of diced tomatoes with their juices. Pour in the broth and add the Italian seasoning. Taste and add more salt and pepper if needed.

Bring the mixture to a gentle boil. Add the elbow macaroni and stir to combine.

Reduce heat to low, cover, and simmer for 10 to 12 minutes, stirring occasionally, until the macaroni is tender. If the mixture becomes too thick, add a splash of broth or water.

Remove the pot from heat. Stir in the shredded cheese until melted and creamy. Serve hot.