Yukon gold potatoes, mushrooms, soy sauce, and tomato paste boost umami taste in this hearty winter entrée. If time is a concern, use store-bought, refrigerated mashed potatoes for the topping. A light drizzle of white truffle oil over the finished dish provides an irresistible aroma.
1 1/2 pounds cubed peeled Yukon gold potato
1 1/2 teaspoons salt, divided
2/3 cup low-fat buttermilk
1/4 teaspoon freshly ground black pepper
1/8 teaspoon ground nutmeg
Dash of ground red pepper
1 cup dried petite green lentils
4 cups water
1/2 teaspoon salt
1 bay leaf
2 1/2 cups organic vegetable broth, divided
3 tablespoons all-purpose flour
1 tablespoon olive oil
1 1/2 cups finely chopped onion
1 cup finely chopped carrot
1/2 cup thinly sliced celery
4 (4-ounce) packages presliced exotic mushroom blend (such as shiitake, cremini, and oyster)
2 tablespoons dry sherry
1 tablespoon soy sauce
1 tablespoon tomato paste
1 teaspoon fresh thyme leaves
1 tablespoon white truffle oil
Chopped chives (optional)
How to Make It
To prepare topping, place potato and 1 teaspoon salt in a medium saucepan; cover with water. Bring to a boil. Cook 20 minutes or until very tender; drain. Return potato to pan. Add buttermilk, 1/2 teaspoon salt, black pepper, nutmeg, and red pepper to potato; mash with a potato masher until smooth. Set aside.
Preheat oven to 375°.
To prepare filling, combine lentils, 4 cups water, 1/2 teaspoon salt, and bay leaf in a saucepan; bring to a boil. Reduce heat, and simmer for 25 minutes or until lentils are tender. Drain, and set aside.
Combine 1/2 cup vegetable broth and flour in a small bowl, stirring with a whisk until well blended. Set flour mixture aside.
Heat olive oil in a large skillet over medium heat. Add onion, carrot, celery, and mushrooms; cook for 7 minutes, stirring occasionally. Stir in remaining 2 cups broth. Add sherry, soy sauce, tomato paste, thyme, and lentils to mushroom mixture. Bring to a simmer over medium-high heat. Stir in flour mixture, and cook until mixture thickens (about 2 minutes), stirring constantly with a whisk.
Spoon lentil mixture into a 2-quart casserole; top with potato mixture, spreading evenly. Bake at 375° for 25 minutes or until potatoes are golden. Drizzle truffle oil over potatoes. Garnish with chopped chives, if desired.