This is a fabulous vegetarian gravy from Gourmet Magazine (November 2004). Using the roasted vegetable stock (Recipe #356871) adds a great complexity, depth of flavour, and overall deliciousness from the vegetable caramelization. The vegetable stock takes some time, but once it's prepared, the gravy is a snap. It's also a great dipping sauce for bread and cooked vegetables. Cooks' note: Gravy can be made 1 day ahead and cooled completely, uncovered, then chilled in an airtight container. Reheat in a saucepan over moderately low heat.