Heat the butter in a large pot or Dutch oven over medium-high heat.
Add the mushrooms and cook for until they start to brown, about 3-4 minutes. Reduce the heat to medium-low and add the onion and carrots. Cook, stirring occasionally, until the vegetables soften, about 8-10 minutes. Add the garlic and cook until fragrant, about 60 seconds. Add the flour, cooking and stirring for about 2 minutes. Pour in the chicken broth while stirring to combine, scraping any brown bits off the bottom of the pan. Simmer until thickened.
Reduce the heat to low and stir in the cream, peas, and cooked turkey. Continue cooking and stirring until the turkey and peas have warmed through. Season with salt and pepper, adding more to taste if needed. If the mixture thickens to much, add some additional broth or cream.
Top with fresh parsley and serve over biscuits or egg noodles.