2 portabella mushrooms 1/3 cup olive oil 2 tablespoons balsamic vinegar 2 teaspoons Dijon mustard 1/4 teaspoon salt 1/4 teaspoon ground black pepper 1 teaspoon minced garlic 1 teaspoon minced shallot or onion 2 ounces Asiago cheese     Preheat an oven to 375 degrees Fahrenheit Carefully remove the stems from the mushrooms. Inspect the mushrooms closely and, if needed, wash in cool water and pat dry. Heat 2 tablespoons of the olive oil in a heavy ovenproof skillet. Add the mushrooms and sauté for 5 minutes turning the mushrooms once. Place the skillet, with the mushrooms in it, in the preheated oven roast the mushrooms for approximately 15 minutes. While the mushrooms are roasting make the vinaigrette: In a small bowl combine the remaining olive oil, Dijon mustard, salt, pepper, garlic and shallot. Whisk together and leave at room temperature until the mushrooms are cooked. Remove the mushrooms from the oven and slice them into 1/4-1/2 inch slices. Fan the mushrooms across two warm serving plates and drizzle with some, or all, of the vinaigrette. Using an ordinary vegetable peeler, peel thin slices of the Asiago cheese and arrange across the mushrooms.