Preheat your oven to 350°F (180°C). Place the pie crust in a 9-inch pie dish and set aside.
In a large bowl, whisk together the eggs, milk or cream, salt, and pepper. Stir in the ham, cheese, and onions or bell peppers (if using). Pour the mixture into the prepared pie crust.
Bake the quiche for 35-40 minutes, or until the edges are golden brown and the center is set.
Remove the quiche from the oven and let it cool for a few minutes before slicing and serving.
You can also add other ingredients to the quiche, such as diced vegetables, cooked sausage, or even seafood. Just be sure to cook any raw ingredients before adding them to the quiche mixture. Enjoy!