Melt 3 tablespoons of butter in a pan. Sauté onion, garlic, mushrooms & thyme until tender. Remove from pan. Add the rest of the butter and rice. Stir until rice looks translucent about 4 minutes.Add wine and stir until absorbed. Add broth, one cup at a time. Let each cup of broth absorb before you add the next cup. Continue to stir. After the last cup of broth is absorbed, add the mushroom mixture, heavy cream, parmesan, salt and pepper. Stir for about 5 minutes.Serve immediately. Top with additional parmesan and chopped parsley.