Preheat the oven. Set to 375°F (190°C). Lightly grease a standard 12-cup muffin pan with butter or nonstick spray.

Prep the crust (or go crustless). If using pie crust, unroll it and cut out 12 rounds with a 3-inch cutter (a jar lid works too). Press gently into each muffin cup. For crustless, skip this step and just grease the pan well.

Cook or warm the ham (optional but helpful). Briefly sauté the diced ham in a dry skillet for 2–3 minutes to render a bit of fat and boost flavor. Let it cool slightly.

Whisk the custard. In a bowl, whisk the eggs, milk or half-and-half, salt, pepper, and any optional seasonings (garlic powder, paprika, or Dijon). Aim for a smooth, uniform mixture without overbeating.

Layer the fillings. Divide the ham, cheddar, and green onions evenly among the muffin cups. Don’t overpack; leave space for the custard to set.

Pour the egg mixture. Fill each cup to about 3/4 full. Give the pan a gentle tap on the counter to release any air bubbles.

Bake. Place on the middle rack and bake for 16–20 minutes, until the centers are just set and a slight jiggle remains. Crust edges should be lightly golden if using crust.

Cool briefly. Let the mini quiche rest in the pan for 5 minutes. Run a thin knife around the edges to release them, then transfer to a rack.

Serve. Enjoy warm or at room temperature. Add a sprinkle of extra chives or a dash of hot sauce if you like.