In a large pot, heat the olive oil over medium heat. Add the diced onion and sauté until translucent, about 5 minutes.
Stir in the minced garlic and cook for an additional 1 minute until fragrant.
Pour in the vegetable broth and bring to a boil. Once boiling, add the cheese tortellini and cook according to package instructions (usually about 3-5 minutes until they float to the top).
Reduce the heat to low and stir in the heavy cream and pesto, mixing well until combined.
Add the baby spinach and cherry tomatoes, then season with salt and pepper to taste. Cook for another 2-3 minutes until the spinach wilts slightly.
Serve hot, garnished with grated Parmesan cheese and fresh basil leaves.
Notes
Feel free to use homemade pesto for a fresher taste.