Ginger-Sesame-Glazed Portobello Steaks

An aromatic marinade adds complexity to these mushrooms, which resemble flank steak when sliced at an angle.

In small bowl, combine garlic, ginger and tahini. Stir in tamari, sesame oil, sugar and wine until well blended.
Put mushroom caps in shallow bowl. Add tamari mixture, turning to coat mushrooms and let stand 15 to 30 minutes, turning once.
In large skillet, heat peanut oil over medium-high heat. Add mushrooms (reserve marinade) and cook, turning once, until browned and slightly softened, about 5 minutes.
Cut each mushroom on a slight angle into 1/4-inch-thick slices. In small saucepan, heat reserved marinade.
To serve, spoon hot mashed potatoes on serving plates. Fan out mushroom slices over potatoes and lightly drizzle with marinade.