Make the crust: In a bowl, mix the flour and salt. Cut in the butter using a pastry cutter or your fingers until the mixture looks crumbly. Add ice water one tablespoon at a time until the dough just comes together. Shape it into a disc, wrap it, and chill for 30 minutes.
Preheat your oven to 375°F (190°C). Roll out the chilled dough on a lightly floured surface and cut circles large enough to fit into a mini muffin pan. Press each round gently into the cups.
In a bowl, whisk together the eggs, milk, salt, and pepper. Stir in the cheese and any fillings you like.
Pour the mixture evenly into the prepared crusts, filling each about three-quarters full.
Bake for 18 to 20 minutes, or until the centers are set and the tops are lightly golden.
Let them cool for a few minutes before removing from the pan. Serve warm or at room temperature.