Ingredients
¼cupall purpose flour,(plus 2 tbsp)
4tbspunsalted butter,(½ stick), soft
3½cupslow salt vegetable stock,or water
1cupwhite wine
8ozbaby carrots,(about 2 cups)
8ozcremini,(about 2 cups), or button mushrooms, halved, or quartered if large
4stalkscelery,(about 2 cups), cut into 1 inch lengths
1bay leaf
½tspsalt
⅛tsppepper
8ozgreen beans,(about 2 cups), cut into 2 inch lengths
1cupfrozen pearl onions
1½cupscups frozen peas
½cupwhole milk or cream,optional
2½lbsYukon gold potatoes,(about 4 very large potatoes), peeled and cut into 2 inch pieces
2½tspsalt
1cupmilk
3tbspunsalted butter,cut into 2 or three pieces
⅛tspground black pepper
2⅓cupsgrated sharp cheddar
½bunch scallions,finely chopped
½cupfresh parsley,chopped
Preparation
Make the buerre manié: In a small bowl, stir the butter and flour together until blended and set aside.
In a large pot, bring the stock and wine to a simmer. Add the carrots, mushrooms, celery, bay leaf, salt, and pepper.
Cook at a low boil for 15 minutes. Add the green beans to the pot and cook for 5 minutes longer, or until the vegetables are tender.
With a slotted spoon, transfer the celery, carrots, green beans, and mushrooms to the baking dish, blotting each spoonful on a folded paper towel to drain excess liquid. Leave the broth in the pan.
Distribute the frozen onions and frozen peas over the vegetables in the baking dish. Remove the bay leaf.
Bring the reserved broth in the pot to a boil over medium heat. Stir in the beurre manié. Simmer the sauce, whisking often, until it has thickened. The beurre manié will look clumpy at first but will quickly smooth out as the butter melts into the sauce.
For a richer sauce, stir in the optional milk or cream. Taste and add more salt and pepper, if desired.
Pour the sauce over the vegetables in the baking dish. Stir gently to coat and set aside while finishing the topping.
Adjust the oven rack to the middle position and preheat the oven to 400 degrees F.
In a large pot, cover the potatoes with cold water and add 2 teaspoons of salt. Bring to a boil over high heat. When the water boils, adjust the heat to a simmer.
Simmer the potatoes for 12 to 14 minutes, or until tender when pierced with the tip of a knife. Drain the potatoes in a colander. Return the potatoes to the pot and set it over medium heat.
Stir the potatoes constantly for about 1 minute, or until the liquid in the pot evaporates and the potatoes look dry. Push them to one side of the pot and pour ½ cup of the milk into the empty space.
Cook until the milk is hot, then add the butter pieces. (Hot milk makes the mashed potatoes fluffier.)
Mash the potatoes, milk, and butter with a potato masher. Gradually add enough additional milk to achieve a creamy consistency. Beat with a whisk to lighten the potatoes and smooth them out.
Add the remaining ½ teaspoon salt and pepper. Stir in 2 cups of cheese, scallions, and parsley. Taste and add more salt and pepper, if desired.
Spoon the potatoes over the vegetables in the baking dish. Use a fork to make swirls in the potatoes to create peaks and valleys. Sprinkle the top with the remaining ⅓ cup grated cheese.
Bake for 30 minutes, or until the filling bubbles and the potatoes are golden. Let rest for 10 minutes and serve.
