In a large stockpot or Dutch oven, heat the olive oil over medium heat. Chop onion, carrot, and celery; mince garlic.
Add the onions to the hot oil and cook 2-3 minutes until softened.
Add the garlic, carrots and celery and cook for an additional 3 minutes.
Add the broth, diced tomatoes, oregano, basil, parsley, and thyme to the pot.
Bring the mixture to a boil, then add the tortellini and cook according to the package instructions.
One minute before the tortellini is done, stir in the kale.
Remove from heat and season with salt and pepper to taste.
Serve immediately, topped with freshly grated Parmesan.