Melt butter in a large stockpot or Dutch oven over medium heat. Add onion, mushrooms , carrots and garlic. Cook , stirring occasionally, until the onions are translucent and the mushrooms and carrots are tender (approx. 10 min). Stir in thyme and red pepper flakes until fragrant (approx.1 min.).

Whisk in flour until lightly browned (approx. 1 min). Add chicken stock and bay leaf, whisking constantly, until slightly thickened (approx. 5 min). Add tortellini and bring to a near boil, reduce heat and simmer until the tortellini is tender ( approx. 5 mins).

Stir in half and half until heated through ( approx. 1-2 mins) . Remove from heat. and remove bay leaf. Add in spinach and stir until it begins to wilt. Season with salt and pepper to taste. Serve immediately .Garnish with grated Parmesan cheese.