Wrap unbaked torta in plastic wrap, and store up to two days in the fridge or up to one month in the freezer. You can also bake the torta ahead and warm just before serving.
- To make Crust: Place flours, oil, and salt in bowl of stand mixer with paddle attachment. Slowly drizzle in 7 to 9 Tbs. ice water with machine running on medium-low speed. Mix 5 to 7 minutes, or until smooth, pliable dough forms. Divide into 2 balls, cover in plastic wrap, and let sit at room temperature 1 hour, or in refrigerator overnight.
- To make Filling: Toss chard with salt in bowl. Transfer to colander, and let stand 1 hour. Place on clean kitchen towel, roll up tightly, and squeeze out as much liquid as possible. Transfer to large bowl.
- Combine potato and enough water to cover by 1 inch in small saucepan. Bring to a boil, then reduce heat to medium-low, and simmer 5 minutes. Drain, and add to chard.
- Heat 2 Tbs. oil in large skillet over medium-high heat. Add leeks, and cook
5 to 7 minutes, or until soft. Add mushrooms, and cook 5 to 7 minutes, or until most mushroom liquid has evaporated. Stir in garlic and nutmeg, and cook 1 minute more. Add leek mixture to bowl with chard, stir, and cool 20 minutes. Stir in eggs until well combined, then stir in Asiago and Parmesan. Season with salt and pepper, if desired.
- Preheat oven to 375°F, and line 12-inch round pizza pan with parchment paper. Roll 1 dough ball into 13-inch circle on floured work surface (don’t worry if dough resists a little). Let dough rest 10 minutes, then continue to roll and stretch (dough will be extremely thin). Gently roll dough circle onto rolling pin, then unroll onto parchment. Top dough with Filling, leaving 1-inch border. Roll out remaining dough round in same manner, and drape over Filling. Seal torta by crimping bottom dough over top layer or by rolling together in rope pattern. Drizzle remaining 1 Tbs. oil over top Crust, and rub in evenly with hands. Cut several vents in top Crust, and bake 50 to 60 minutes, or until bottom Crust is golden brown. Serve hot, at room temperature, or chilled.