For quiche that sets perfectly -- with a soft but not runny egg custard -- you need to cook broccoli, whether frozen or fresh, before baking the quiche. Originally from the Alsace-Lorraine region of northeastern France, a traditional quiche Lorraine contains bacon bits and Swiss or Gruyere cheese. But quiche presents an open canvas for any ingredients you wish to add to the broccoli.
Getting Into Hot Water
Since the broccoli will cook once it's in the quiche, you only want to partially cook it beforehand. Parboiling begins with a large pot of salted boiling water -- size is important because with more water to begin with, the less heat the water will lose once you drop in the frozen broccoli. Cook the broccoli for one to two minutes until it is almost tender and enables you to pierce it partially with the tip of a knife.
Shock Your Broccoli
To stop the broccoli from becoming overcooked and turning a drab green, drain the spears from the boiling water and plunge them immediately into a large bowl of ice water that you have prepared before beginning to cook. Leave them immersed for about two minutes. Ice water not only stops the broccoli from cooking any further, but it cools the spears quickly by forcing residual heat inside the broccoli to travel to the outside.
To the Chopping Block
Before chopping the broccoli spears for the quiche, squeeze them gently in a clean dish towel to remove as much water as possible. It's best to cut the broccoli into bite-size pieces so you don't need a knife when eating the quiche. Chop the stems and florets into 1/2-inch pieces. Depending on the size of your quiche, use about 1 1/2 cups of broccoli and save one or two extra florets as a garnish for the top of the quiche.
Broccoli Buddies
While you can make a quiche without cheese, it pairs well with broccoli and gives your quiche a rich creaminess. Cheddar, feta, goat, Parmesan or Swiss cheese all taste good with broccoli. Herbs such as basil, coriander, oregano, parsley, tarragon or thyme also complement the flavor of broccoli. Choose one or two herbs to give the quiche more depths of flavor. You'll also never go wrong with a few bacon or ham pieces scattered across the quiche with a light hand.