Step 1: Prepare the Crust

1. Preheat your oven to 375°F (190°C).
2. Roll out the pie crust and fit it into a 9-inch pie dish. Trim and crimp the edges as desired.
3. Prick the bottom of the crust with a fork to prevent puffing. Bake for 8–10 minutes, or until lightly golden. Remove and let cool.

Step 2: Make the Filling

1. In a large mixing bowl, whisk together the cream cheese and sour cream until smooth.
2. Add the eggs, milk, garlic powder, onion powder, salt, and black pepper. Whisk until well combined.
3. Fold in the cheddar cheese, Monterey Jack cheese, diced ham, and green onions.

Step 3: Assemble the Quiche

1. Pour the filling into the pre-baked pie crust, spreading it evenly.
2. Sprinkle additional shredded cheese or sliced green onions on top for garnish, if desired.

Step 4: Bake

1. Place the quiche on the middle rack of the preheated oven and bake for 40–45 minutes, or until the center is set and the top is golden brown.
2. Remove from the oven and let the quiche rest for 10 minutes before slicing and serving.