You need to saute the broccoli. Put it in a small skillet over medium heat and stir frequently. Let it cook for about 5 minutes or until the broccoli is softened but still slightly crunchy.
Preheat your oven to 375 degrees F and place a baking sheet on the bottom rack of your oven to catch any drips during baking. Then, in a large bowl, mix together the softened butter, salt, pepper, and onion powder.
Add to the butter mixture and stir until evenly coated. Place pie crust in a 9-inch pie pan and spread the broccoli mixture around the bottom of the crust.
Sprinkle the cheddar cheese over the broccoli and spread evenly. In a separate bowl, whisk together eggs and milk until fully combined.
Pour egg mixture into pie pan on top of broccoli and cheese. Bake in preheated oven for about 35-40 minutes or until the quiche is golden brown. Allow the quiche to cool for 10 minutes before slicing and serving.