Mushroom Potpie

Ingredients
4 tablespoons olive oil
1 1⁄2 pounds mushrooms (cremini or button, halved or quartered if large)
4 carrots (cut into 1/2 inch pieces)
3 celery stalks (sliced 1/4 inch thick)
1 onion (medium size, chopped)
1⁄2 teaspoon thyme
1 teaspoon salt
1 teaspoon pepper
1⁄3 cup flour
1 1⁄2 cups vegetable broth
1 cup frozen peas
1 slice puff pastry (half a 17.3 ounce package, thawed)
1 small head romaine (leaves from)
1⁄3 cup roasted almonds (chopped)
2 tablespoons red wine vinegar
Instructions

1. Heat oven to 400° F. Heat 2 tablespoons of the oil in a large skillet over medium-high heat. Add the mushrooms, carrots, celery, onion, thyme, 1/2 teaspoon salt, and 1/4 teaspoon pepper. Cook, stirring occasionally, until the vegetables are tender, 12 to 15 minutes. Add the flour and cook, stirring, for 30 seconds. Add the broth and peas; bring to a boil.

2. Transfer the mushroom mixture into an 8-inch square baking dish. Lay the pastry on top and cut several vents in it. Place the baking dish on a rimmed baking sheet and bake until the crust is golden, 25 to 30 minutes. Let rest 15 minutes before serving.

3. Meanwhile, in a large bowl, toss the romaine with the almonds, vinegar, the remaining 2 tablespoons of oil, and 1/4 teaspoon each salt and pepper. Serve with the potpie.