White Mushrooms on Toast

From Alex Guarnaschelli's Old School Comfort Food

• Ready In: 45 mins
• Serves: 8

Ingredients

• 3  tablespoons  extra-virgin olive oil
• 1  small yellow onion, finely diced
• 2  small garlic cloves, minced
• 3⁄4 lb white mushroom, stemmed, washed, dried and thinly sliced
• 2  tablespoons dry marsala wine
• 1⁄2 cup sour cream
• 1  tablespoon  chopped fresh tarragon
• 16  slices baguette, cut 1/2 inch thick

Directions

1. Preheat the oven to 375°F.
2. Arrange the bread slices in a single layer on a baking sheet and brush with 1 tablespoon olive oil. Bake until lightly browned and crispy, 6 to 8 minutes.
3. Heat a large saucepan over medium heat. Add 2 tbsp of the olive oil and the diced onion. Season with salt and pepper and cook until tender, 3-5 minutes. Add the minced garlic and lower the heat. Add the mushrooms and season with salt and pepper. Cook until the mushrooms are tender and a lot of the liquid has evaporated at the bottom of the pan, 8-10 minutes.
4. Add the Marsala to the mushrooms and cook until the flavor of the alcohol has mellowed considerably, 5-8 minutes. Add the sour cream and allow it to melt over the mushrooms. Check the seasoning. Add the tarragon. Taste for seasoning. Bring to a simmer and serve on toast immediately.