cream of mushroom recipe

Ingredients: 1 pound mushrooms, sliced (you can use a mix of varieties like cremini, button, or shiitake) 2 tablespoons unsalted butter 1 medium onion, finely chopped 3 cloves garlic, minced 2 tablespoons all-purpose flour 4 cups chicken or vegetable broth 1 cup heavy cream 1/2 cup whole milk 1 teaspoon dried thyme