Melt butter in a large stockpot or Dutch oven over medium heat. Add onion, carrots and celery. Cook, stirring occasionally, until tender, about 3-4 minutes.
Stir in garlic and Italian seasoning until fragrant, about 1 minute.
Whisk in flour until lightly browned, about 1 minute.
Stir in wine, scraping any browned bits from the bottom of the pot.
Stir in chicken stock and bay leaf; season with salt and pepper, to taste. Bring to boil; reduce heat and simmer, covered, until flavors have blended, about 10 minutes.
Stir in chicken and tortellini and cook until tender, about 4-5 minutes.
Stir in heavy cream, peas, lemon juice and parsley until heated through, about 2 minutes; season with salt and pepper, to taste.