Preparation

• Position a rack in the center of the oven and heat to 375°F. Line a large rimmed baking sheet with foil, and lightly brush with oil.
• Core the tomatoes and halve them lengthwise. Nudge out some of the seeds with your finger; don’t be too thorough because you want to retain some of the moisture in the pulp. Put the tomatoes close together, cut side up, on the prepared baking sheet. Sprinkle with 1 tsp. salt and 1/2 tsp. pepper, and drizzle with the oil.
• 烤西红柿，直到枯萎并在底部略微烧焦，约90分钟。将床单转移到电线架上，然后立即在每个番茄下方滑动黄油刀或刮刀，以松开，然后完全冷却。（西红柿可以提前几天制作，并在冰箱中存放，覆盖。）
• Melt the butter in a large skillet over medium-low heat. Add the onions and salt to taste, and cook, stirring occasionally, until caramelized, adding water as needed to prevent the onions from sticking to the pan, about 60 minutes. Add the garlic and cook, stirring, until the garlic becomes fragrant and softens, about 30 seconds; set aside.
• Whisk the Parmigiano, cornmeal, rosemary, 1/4 tsp. salt, and 1/8 tsp. pepper in a small bowl.
• 在另一个小碗中搅拌奶油，蛋黄酱和芥末。
• On a lightly floured surface, roll the dough into a circle approximately 13 inches in diameter. Transfer the dough to a standard (not deep dish) 9½ -inch pie plate. Gently tuck the pastry into the pan without stretching it, then折叠边缘并压接。冷藏30至45分钟的馅饼外壳。将两个架子放在烤箱中，一个架子在底部的三分之一，另一个在中心，然后加热至375°F。
• 将馅饼壳放在有框的烤盘上。将Parmigiano混合物的三分之一均匀地撒在馅饼壳的底部，然后用1/2杯切达干酪盖住。将一半的西红柿放在奶酪上的均匀层中，然后将另外三分之一的帕米亚诺混合物，然后是一半的洋葱。将一半的奶油混合物倒在洋葱上，然后再倒另外1/2杯切达干酪，剩余的西红柿和剩下的三分之一的帕米亚诺混合物。在其余的洋葱和剩余的奶油混合物中层层。顶上最后1/2杯切达干酪，使用叉子将其轻轻压入奶油中。
• 将馅饼在纸张上的馅饼转移到烤箱的底部架子上，烘烤30分钟，然后将馅饼移至中心架。烘烤直到地壳变成金色，再增加20分钟。上菜前转移到电线架中，冷却至少15分钟。