Cook turkey in a Dutch oven over medium heat, about 7 minutes. Break the pieces apart into smaller pieces as it is cooking. Try to make the pieces as small as possible.
Add onion, water, chili, salt, garlic powder and cumin to the Dutch oven. Stir to combine. Bring to a boil and reduce heat. Simmer for until most of the liquid has been absorbed, about 15 minutes. Remove from heat.
Divide spinach evenly among 4 bowls. Place ¼ of the diced tomatoes each of the bowls. Divide the taco meat evenly among the 4 bowls. Sprinkle the meat with the cheese. Top each bowl with the ¼ cup of croutons.
Serve.
Recipe by The Little Chef at http://littlechefblog.com/taco-salad/