Sausage and Sweet Potato Soup - Paula Deen

Ingredients

• 1 teaspoon Olive oil
• 1½ pounds Italian sausage, casings removed
• 2 cups chopped yellow onion
• ½ cup chopped celery
• 1 tablespoon minced garlic
• 2 pounds sweet potatoes, peeled and chopped
• 1 pound russet potatoes, peeled and chopped
• 3 (32-ounce) containers low-sodium chicken broth
• 1 (14.5-ounce) can diced fire-roasted tomatoes
• 10 sprigs fresh thyme, tied with kitchen string
• 4 cups (2-inch pieces) kale
• 1 teaspoon Kosher salt
• ½ teaspoon ground black pepper
• shredded Parmesan cheese