4 tablespoons (1/2 stick) butter

1 pound oyster mushrooms, halved if large

1 tablespoon minced garlic

4 cups thinly sliced leeks (white and pale green parts only; about 4 large)

1 tablespoon minced fresh thyme

1 3/4 cups canned low-salt chicken broth

1 3/4 cups whipping cream

1/4 cup dry white wine

1 teaspoon salt

1/2 teaspoon ground black pepper

3 3/4 pounds russet potatoes, peeled, thinly sliced into rounds (about 8 cups)

2 1/2 cups grated Gruyère cheese (about 10 ounces)

Melt 2 tablespoons butter in heavy large skillet over medium-high heat. Add mushrooms and sauté until almost tender, about 5 minutes. Add garlic and sauté until mushrooms are tender and golden, about 3 minutes longer. Transfer mushroom mixture to bowl. Melt remaining 2 tablespoons butter in same skillet over medium-high heat. Add leeks and thyme and sauté until leeks are tender and beginning to brown, about 8 minutes. Add leek mixture to bowl with mushrooms. (Can be made 1 day ahead. Cover and refrigerate.)

Preheat oven to 400°F. Butter 13 x 9 x 2-inch baking dish. Whisk broth, cream, wine, 1 teaspoon salt and 1/2 teaspoon pepper in large bowl to blend. Layer 1/3 of potatoes on bottom of prepared dish. Top with half of mushroom-leek mixture, then 3/4 cup cheese. Top with half of remaining potatoes. Pour half of cream mixture over. Top with remaining mushroom-leek mixture and 3/4 cup cheese. Cover with remaining potatoes. Pour remaining cream mixture over; sprinkle with remaining cheese.

Bake gratin uncovered until potatoes are tender and sauce bubbles thickly, about 1 hour 20 minutes. Let gratin stand 30 minutes before serving.


Prep time:  15 mins
Cook time:  45 mins
Total time:  1 hour
Serves: 3 as a meal
 
1 pound potatoes, cleaned and halved (or cubed, depending on their size)
4-5 medium-sized carrots, cleaned and chopped into roughly the same size pieces as your potatoes (so that they roast evenly)
2 large leeks, cleaned and cut into 1-1/2 inch pieces (leave the tough green parts behind)
5 cloves of garlic, left in the peel
⅓ cup olive oil
1 teaspoon kosher salt
1 teaspoon smoked paprika
½ teaspoon ground cumin
¼ teaspoon cayenne pepper (or more, if you like it spicier, like me)
¼ teaspoon ground black pepper
a small pinch of cinnamon
a small pinch of granulated sugar
8-9 cups vegetable stock
grated carrots, for garnish

Preheat your oven to 400 degrees F. Place all of your chopped vegetables on a baking sheet, along with your garlic cloves, still in their peels, and drizzle with your olive oil, then sprinkle with your spices. Roast the vegetables for 30 minutes or so, until fork-tender.
Place all of the vegetables and peeled garlic in your food processor (working in batches, if you need to, or use an immersion blender), and pulse with a bit of your stock until smooth. Add a cup of stock at a time, pulsing, until you've reached your processor's maximum capacity (which is why I love my immersion blender - no maximum capacity), then push the pureed vegetables through a mesh sieve (or not, but I prefer a smoother texture). Place in a large pot, add the rest of your stock, and bring to a simmer. Taste and adjust seasonings as needed. This will keep well in the fridge for a week, or frozen for 3 months.