Bring 1 1/2 cups water to a boil in a medium saucepan. Add wild rice; cover, reduce heat, and simmer 1 hour or until tender. Set aside.
Cook the sausage in a Dutch oven over medium-high heat until browned; stir to crumble. Drain sausage; set aside.
Heat oil in Dutch oven over medium-high heat. Add onion, and sauté for 3 minutes. Add garlic, and sauté for 1 minute. Add the sausage, 3 cups water, and the next 5 ingredients (water through tomatoes); bring to a boil. Reduce heat; simmer for 20 minutes. Stir in cooked wild rice, spinach, salt, and pepper. Ladle soup into bowls; sprinkle with cheese.