Oh, Martha Stewart, why do you make such good things? I think you often over complicate your recipes, but with this quiche, you hit the money.
Quiches are one of those adaptable foods that you can alter to suit your own taste. Basically you can plug in different ingredients like this; pick at least one ingredient from each of the following categories:
Aromatic - onion, shallots, scallions, etc.
Cheese - Parmesan, Gruyere, Romano, Asiago, etc.
Filling(s) - mushroom, zucchini, broccoli, spinach, kale, arugula, shredded carrot, sausage, bacon, prosciutto, chicken, etc. (Precook the meat or use cured meat before adding it to the egg mixture.)
The veggies will have to be at least half cooked otherwise they will be crunchy. Quiches should not be crunchy. And when you see the heavy cream listed among the ingredients, don't freak out. This 1980's non-fat/low-fat fad is outdated garbage. If you're going to take the time to make food, use the best ingredients; and that means using real butter or cream sometimes (for example). I'm not talking about in excess. Paula Dean is a forerunner for heart disease, but in moderate portions, you can eat anything and be perfectly fine.
Here's the recipe. Martha uses morel mushrooms, but obviously you can choose a more affordable mushroom for this quiche. With this quiche base, you could put in whatever filler ingredient you want. I used shiitake mushrooms, red onion, and spinach. You could use zucchini and prosciutto OR shallot, bacon, and arugula OR just broccoli. Try this recipe word for word, ingredient for ingredient to see if you like it. Then experiment, experiment, experiment to make it your own. I found that Martha uses too much salt, so I cut back by half. The cheese adds a lot of salt, too.
This recipe makes one tall quiche or two shorter quiches. I like splitting the filling into two crusts because we like a little more crust in our household. See, it's all about adaptability. Give it a try. This recipe is definitely one to make to impress the in-laws.