Heat olive oil in a large pot over medium heat.
Add chopped onions and sauté until translucent.
Stir in minced garlic and cook for an additional minute.
Add diced tomatoes and cook for 5 minutes.
Pour in the broth and bring to a simmer.
Add the tortellini and cook according to package instructions.
Add spinach or kale and stir until wilted.
Season with Italian seasoning, salt, and pepper to taste.
Remove from heat and let cool slightly.
Serve hot, garnished with fresh parsley.