Sauteed Portabella and Cremini Mushrooms - portabella mushrooms

Method

• Halve portabellas and cut into 1/4-inch-thick slices.
• Cut cremini into 1/4-inch-thick slices.
• Chop shallots and in a 12-inch heavy skillet cook half of shallots in half of butter over moderate heat, stirring, 1 minute.
• Add portabellas and salt and pepper to taste and cook, stirring occasionally, until liquid mushrooms give off is evaporated, about 15 minutes.
• Transfer portabellas to a bowl and keep warm, covered.
• Cook remaining shallots in remaining butter over moderate heat, stirring, 1 minute.
• Add cremini and salt and pepper to taste and cook, stirring occasionally, until liquid mushrooms give off is evaporated, about 10 minutes.
• Add portabellas to cremini and keep warm, covered.
• Mushrooms may be prepared up to this point 1 day ahead and chilled, covered.
• Diagonally cut scallions into thin slices.
• In a bowl whisk together vinegar, soy sauce, and sugar.
• Heat mushrooms over moderately high heat until hot and add vinegar mixture.
• Boil mixture 3 minutes, or until liquid is reduced slightly, and stir in scallions.