Preheat the oven to 425 degrees F (220 degrees C).
Place hash browns in a medium bowl. Melt 5 tablespoons butter and pour over hash browns, season with seasoning salt or garlic powder as desired.
Add 1 egg to hash brown mixture, mix well and press mixture onto the bottom and sides of a 9-inch spring form pan or pie dish.
Bake in preheated oven until potatoes are golden brown and crispy around the edges, about 25 to 30 minutes.
While crust bakes, melt remaining tablespoon of butter in a medium skillet over medium-high heat.
Add ham, pepper, and green onion to skillet; cook and stir until bell pepper slightly softens, about 4 minutes. Remove from heat.
When crust is ready, spread ham mixture over the bottom; sprinkle cheese evenly on top.
Whisk remaining 5 eggs and cream in a medium bowl; add salt and pepper to taste and mix until well blended.
Pour egg mixture evenly over ham and cheese mixture.
Reduce oven temperature to 350 degrees F (175 degrees C).
Bake in the preheated oven until filling is puffed and quiche is lightly browned around the edges, about 35 minutes.
