Preheat and prep: Heat the oven to 375°F (190°C). Lightly grease a standard 12-cup muffin tin, or use a mini muffin tin for bite-sized quiches.

Cook the bacon: In a skillet over medium heat, cook the chopped bacon until crisp. Remove to a paper towel-lined plate. Pour off all but 1 teaspoon of bacon fat.

Sauté the onion: Add the minced onion or shallot to the pan and cook until soft and lightly golden, 3–5 minutes. Let cool slightly.

Make the custard: In a bowl, whisk the eggs with the cream until smooth. Season with 1/2 teaspoon salt, several grinds of black pepper, and a pinch of nutmeg.

Roll the pastry: On a lightly floured surface, roll out the pie crust to about 1/8 inch thick. Use a round cutter (about 3 inches for standard muffin tins, 2 inches for mini tins) to punch out circles.

Fit the cups: Press the pastry circles gently into the muffin cups, making sure the dough reaches the top edge. If the dough shrinks, patch with scraps. Prick the bottoms with a fork.

Optional blind bake: For extra-crisp crust, bake the empty shells for 7–8 minutes, then cool slightly. This step helps prevent soggy bottoms.

Fill the shells: Divide the bacon and sautéed onion evenly among the pastry cups. Top with grated cheese, leaving a little room for the custard.

Add the custard: Pour the egg mixture into each cup, about 3/4 full. Don’t overfill—custard puffs as it bakes.

Bake: Bake standard minis for 18–22 minutes (mini muffin size 12–15 minutes), until the centers are just set and the tops lightly golden. A slight jiggle is fine; they finish setting as they cool.

Cool and serve: Let the quiches rest in the pan for 5 minutes, then loosen edges with a butter knife and lift out. Garnish with chopped chives or parsley if you like. Serve warm or at room temperature.