Make Portobello Gravy.
Place potatoes and garlic in a large pot, cover with lightly salted water and bring to a boil. Cover and cook over medium heat until the potatoes are tender, about 20 minutes. Drain, reserving cooking liquid.
Return the potatoes and garlic to the pot. Add butter (or oil). Mash the potatoes with a potato masher, adding 1/2 to 1 cup of the reserved liquid to make a creamy consistency. Season with salt and pepper. Transfer the mashed potatoes to a warmed serving bowl and serve with Portobello Gravy.Portobello GravyActive time: 10 minutes | Total: 30 minutes 1 tablespoon extra-virgin olive oil1 medium onion, finely chopped2 cloves garlic, minced1 1/2 cups chopped cleaned portobello mushrooms (2 medium)2 1/4 cups vegetable broth (see Ingredient note)3 tablespoons tamari or reduced-sodium soy sauce 1/4 teaspoon dried thyme leaves1/8 teaspoon crumbled dried sage1 tablespoon cornstarch 2 tablespoons waterFreshly ground pepper to taste
Heat oil in a medium saucepan over medium heat. Add onion and garlic; cook, stirring often, until softened, about 5 minutes. Add mushrooms and cook, stirring often, until they begin to release their juices, about 10 minutes.
Add broth, tamari (or soy sauce), thyme and sage; simmer for 10 minutes. Mix cornstarch and water in a small bowl. Stir into the sauce and simmer, stirring often, until slightly thickened, about 10 minutes more. Season with pepper. If you prefer a smooth gravy, pass it through a fine sieve (discard mushrooms and onions). Serve hot.Makes 2 cups chunky gravy or 1 cup smooth gravy, for 8 servings.
Ingredient note: Commercial vegetable broth is readily available in natural-foods stores and many supermarkets. We especially like the Imagine and Pacific brands, sold in convenient aseptic packages that allow you to use small amounts and keep the rest refrigerated.