Porcini Mushroom Latkes with Mushroom Salad and Chive Cream

Name: Porcini Mushroom Latkes with Mushroom Salad and Chive Cream
Ingredients: 1 ounce dried porcini mushrooms; 2 pounds russet potatoes, peeled, cut into 3/4-inch cubes; 2 cups chopped onions, divided; 1 large egg; 1 tablespoon all purpose flour; 1 1/2 teaspoons coarse kosher salt; 1/2 teaspoon freshly ground black pepper; Vegetable oil (for frying); 1 cup nondairy sour cream; 1/4 cup chopped fresh chives; 3 1/2 tablespoons (or more) white wine vinegar, divided; 2 tablespoons olive oil; 3 small garlic cloves, pressed; 8 ounces fresh shiitake mushrooms, stemmed, caps sliced; 8 ounces crimini mushrooms, sliced; 3 cups (packed) baby greens; Ingredient info: Dried porcini mushrooms are available in the produce section of many supermarkets and at specialty foods stores and italian markets.