Add the chopped onion and minced garlic to a pot over medium high heat with a bit of cooking oil. Cook until onion turns translucent, about 1-2 minutes.
Add in the ground turkey and break apart using a spatula. Cook until turkey is no longer pink. Drain any excess grease by swishing a paper towel along the bottom of the pan with the spatula.
Next add the tomato sauce, water, heavy cream, italian seasoning and orzo. Stir together, bring to a very gentle boil then reduce heat to let simmer. Stir frequently with a spatula, scraping along the bottom to prevent the orzo from sticking. Cook until the sauce has reduced and orzo is cooked, about 10 minutes.
Remove the pot from the heat, then mix in the grated parmesan and spinach. Cover and let sit for 3 minutes.
The sauce will begin to thicken as it cools. Scoop into bowls and serve with a sprinkle of parmesan on top.