1 Tbs. chopped fresh rosemary or 1 tsp. dried, crumbled
2 lbs. spinach, stemmed and well washed
3 cups unbleached all-purpose flour
3/4 tsp. salt
3/4 cup plus 3 Tbs. chilled solid vegetable shortening
5 to 6 Tbs. ice water
1 lb. parsnips, peeled and cut into 1/2-inch chunks
2 Tbs. olive oil
1 Tbs. chopped fresh thyme or 1 tsp. dried
2 tsp. coarse salt
1 lb. cremini or button mushrooms, halved or quartered
3/4 tsp. freshly ground pepper
Make pastry crust: In large bowl, mix flour and salt. Cut in shortening with your fingertips until mixture resembles coarse meal. Sprinkle with 3 tablespoons ice water and toss to mix.
Add additional ice water, 1 tablespoon at a time, and work in gently until dough just comes together and isn’t too crumbly. Gather into ball then knead a few times to blend. Cut off one-quarter of dough. Shape both pieces into a disk, wrap in plastic wrap and chill at least 2 hours or up to 2 days.
Preheat oven to 450°F. In large bowl, combine parsnips, 1 teaspoon oil, thyme and 1/4 teaspoon salt and mix well. Transfer to baking sheet with sides and roast 10 minutes.
In same bowl, combine mushrooms, 2 teaspoons oil, 1/2 teaspoon salt and 1/4 teaspoon pepper and mix well. Add to baking sheet with parsnips and roast 8 to 10 minutes. Remove from oven and set aside.
In large pot, combine half the spinach and 1 cup water. Cover, bring to a boil and cook until wilted, about 2 minutes. Remove spinach to colander with tongs, rinse under cold running water and squeeze out as much moisture as possible. Repeat with remaining spinach. Coarsely chop spinach and set aside.
In large saucepan, heat remaining 1 tablespoon oil over medium heat. Add shallots and cook, stirring often, until softened, about 5 minutes. Add flour and cook, stirring, 2 minutes. Gradually whisk in warmed soy milk a bit at a time, letting sauce thicken before adding more milk. When all soy milk is added, reduce heat to medium-low and cook, whisking often, 1 to 2 minutes. Stir in spinach, 1/2 teaspoon salt and 1/4 teaspoon pepper.
Remove pan from heat and allow to cool.
Coat a 4-quart oval or rectangular casserole with vegetable cooking spray. Cut baking potatoes into 1/8-inch-thick slices and place in bowl. Add cold water to cover and let stand 5 minutes. Meanwhile, peel and cut sweet potatoes into 1/8-inch-thick slices.
Drain baking potatoes and arrange slices, overlapping, in bottom of prepared casserole. Sprinkle with rosemary and 1/2 teaspoon salt. Arrange sweet potato slices on top, overlapping. Sprinkle with remaining 1/4 teaspoon salt and 1/4 teaspoon black pepper. Spread spinach mixture evenly over sweet potatoes, then top with parsnips and mushrooms.
Preheat oven to 400°F. On lightly floured surface, roll out larger piece of dough 3 inches larger than shape of casserole. Place dough on top of filling; roll edges under and crimp onto lip of casserole. Roll out remaining piece of dough and, with cookie cutters and pastry wheel or knife, cut out leaves.
With pastry brush, lightly brush top of pie with water, then add pastry leaf decorations. Cut several vents in top crust for steam to escape. Place pot pie on baking sheet and bake until crust is nicely golden and filling is steaming hot, about 1 hour. Let stand 15 minutes before serving.