This rich, earthy gravy can be made with fresh shiitakes as well as portobellos. Leave the mushroom pieces in for a chunky-style sauce or strain them out for a velvety consistency.
Make Ahead Tip: Cover and refrigerate for up to 2 days. Reheat on the stovetop or in the microwave.
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.
People with celiac disease or gluten-sensitivity should use soy sauces that are labeled "gluten-free," as soy sauce may contain wheat or other gluten-containing sweeteners and flavors.
1/2 vegetable, 1/2 fat (per 1/4 cup)