In a large pot over medium heat, melt the butter, then add the onions and garlic and cook, stirring frequently, until softened.
¼ cup butter, 1 medium yellow onion, 2 cloves garlic
Add the mushrooms and continue to cook until the mushrooms have softened and the juices have cooked away, about 10 minutes.
1 lb baby bella mushrooms
Add the white wine and cook until reduced by half, about 5 minutes. Sprinkle the flour and thyme over the veggies and stir to coat. Slowly add the chicken broth, stirring constantly to avoid clumps. Bring to a boil, then turn down to a low simmer until the broth has thickened slightly, about 10 minutes.
3 tablespoons white wine, 5 tablespoons flour, 1 teaspoon dried thyme, 2 cups chicken broth
Add the heavy cream and continue to lightly simmer until desired thickness is reached. Season with salt and pepper to taste.
1 cup heavy cream, Salt and pepper to taste