Prepare Ingredients: Dice the onion, carrots, and celery. Mince the garlic. Remove stems from kale or spinach and chop. If using frozen tortellini, thaw according to package instructions.
Sauté Aromatics: Heat olive oil in a large pot over medium heat. Add diced onion and cook until translucent, about 3-4 minutes. Add minced garlic and cook for an additional 1-2 minutes until fragrant. Add diced carrots and celery to the pot. Sauté for another 3-4 minutes until the vegetables begin to soften.
Add Vegetables: Add diced carrots and celery to the pot. Sauté for another 3-4 minutes until the vegetables begin to soften.
Add Broth and Tomatoes: Pour in vegetable broth and add diced tomatoes (with their juices) to the pot. Stir in dried basil, dried oregano, dried thyme, salt, and pepper. Bring the soup to a boil, then reduce heat to low and let it simmer for about 10 minutes to allow flavors to meld.
Cook Tortellini: Add cheese tortellini to the pot. Cook according to package instructions (usually about 7-9 minutes for fresh tortellini, or longer for frozen). Stir occasionally to prevent sticking.
Add Greens: Once the tortellini is almost cooked, add chopped kale or spinach to the pot. Stir until wilted, about 2-3 minutes.
Adjust Seasoning: Taste the soup and adjust seasoning if needed with more salt and pepper.
Serve: Ladle the soup into bowls. Optionally, garnish with grated Parmesan cheese. Serve hot and enjoy!