Heat a pot to medium-high, add the olive oil, meat, garlic, onion, carrots, and celery, and stir for 4-5 minutes.
Melt the butter into the mixture, then add the diced tomatoes, thyme, tomato paste, and broth. Use a spoon to mix in the cornstarch. Place back onto the heat and allow to simmer for 15-20 minutes.
Add the tortellini to the soup, and place back on the heat for 5 minutes.
Pour in the cream and spinach and return to the stove for 5 minutes or until the spinach is wilted. Taste and add salt and pepper if needed.