For the crust: transfer prepared dough to a pie plate or to tart pan with removable bottom. Do not stretch dough while transferring or pressing into pan. Trim excess dough or roll the crust evenly just above the top of the pan. Place pan in freezer for 20 minutes. Prick bottom of crust with the tines of a fork, then follow package instructions for pre-baking (I baked for 20 minutes at 420℉ with parchment paper and pie weights) 5 minutes before pre-bake time is complete, remove from oven. Remove parchment and pie weights carefully. Brush bottom of the pastry crust with egg white. Return to oven for 5 minutes. (This step creates a seal on the crust that prevents the egg custard from soaking in and creating a soggy shell). Once the pie shell is finished, remove from oven and set aside. Lower oven temperature to 375℉.

For the quiche filling: while the crust is baking, cook shallots in olive oil over medium heat until softened and just browning, about 5-7 minutes. Remove from heat and let cool. Whisk eggs, half and half, Dijon, lemon zest, dill and chives in a medium bowl very well. Season with salt and pepper. Add pinch of cayenne, if using.

Quiche assembly and baking: Layer sautéed shallots into bottom of pre-baked tart shell. Top with shredded Swiss cheese and smoked salmon pieces. Gently pour the egg mixture over the fillings. Ensure dill and chives are evenly distributed across the top. Carefully transfer pie pan (on baking sheet) to center rack of oven.

Bake until center is just set, around 35-45 minutes. Cool the pan on a wire rack for 15 minutes before removing the ring and cutting for service. Serve warm or room temperature.