As the days grow chilly, a hearty soup is welcome at any get-together. Soups are easy to make in advance and need nothing more than a wedge of cheese and a loaf of bread, maybe a bowl of olives and a glass of wine. That’s supper, lunch or an afternoon pick-me-up, served in a generous bowl.For this soup’s inspiration, I turned to the flavors of France’s classic forestiere and Italy’s cacciatore — forest or hunter’s stews — where the woodsy earthiness of mushrooms takes center stage. Starting with an excellent broth takes the soup from dull to dramatic. I recommend chicken broth (homemade, if you can) but substituting vegetable broth (and using vegetarian “fish sauce” in place of the Worcestershire) is how the recipe can be easily adapted for nonmeat eaters. Omit the cream, and the soup can be vegan.In each instance, simmering the broth with the stems of the mushrooms not only uses flavor-filled scraps that might otherwise be discarded, but it also infuses the broth with even more mushroomy depth.I call for cremini mushrooms because they are easy to find in just about any grocery store, although I have often made the recipe with a blend of shiitake, oyster and/or morel mushrooms exchanged or swapped in, ounce for ounce. If you are a forager or know one, chanterelles or hen-of-the-woods mushrooms make the soup spectacularly rich-tasting. Of course, be cautious when foraging, and work with someone knowledgeable before eating any truly wild fungi.What sets this soup apart is umami; here, it is built with layers of care. Deeply browning the mushrooms, melting shallots with butter and garlic and caramelizing tomato paste to concentrate its flavor make it all happen. Those elements, combined with the enriched broth, fashion a soup that is complex — and filling to boot.Make the broth, pan-roast the mushrooms, swirl in some cream — dinner is ready. Whir the same soup in a blender for a velvety texture and call it bisque, an elegant soup that is easy to transport to your next potluck. Garnish portions with a few mushrooms, a dollop of sour cream, a buttery crouton or a scattering of chives.As a bisque, the soup is as smooth as silk. I serve it as an appetite tantalizer for big feasts like Thanksgiving, offering a sipping cup’s worth when guests arrive. It’s a generous welcome that promises more good food ahead.