Mushroom Gruyère Quiche

We made this quiche this weekend and it was pretty good ! I still had a lot of mushrooms from the market, so I only used those (rather than the mixture)- they were white. Next time I might add a little bacon to it, but it was good just as it was. I liked the oven roasting method... it was much quicker and easier than browning in batches in my tiny sauté pan like I did for the mushroom bacon tart. Additionally, I don't have a kitchen scale, so I just kind of guessed on the amount of mushrooms. And I didn't have thyme so I used some herbes de Provence and some fresh Italian parsley. And one more thing- I didn't prebake the shell.

Here's the recipe:

Mushroom Gruyère Quiche
1/4 pound cremini mushrooms, cut into quarters or eighths, depending on size

1/4 pound portobello mushroom caps, diced
1/4 pound shiitake mushrooms, stems removed and discarded, cut into quarters
1/2 medium yellow onion, thinly sliced
1 tablespoon extra virgin olive oil
1/2 teaspoon salt
1/2 teaspoon black pepper
1 frozen 9-inch pie crust, thawed
1/2 cup heavy cream
2 eggs
1 tablespoon chopped fresh thyme
4 ounces gruyère cheese, shredded (about 1.5 cups)
2 teaspoons chopped fresh thyme

Preheat oven to 400°F. In a large bowl, toss cut mushrooms with onion, olive oil, salt and pepper, then place on a rimmed baking sheet in a single layer. Roast for about 15 minutes, or until cooked and firm. Remove from oven and set aside. Prick pie shell all over with a fork. Prebake shell for 10 to 15 minutes, until lightly browned. Reduce oven temperature to 350°F. Whisk together heavy cream and eggs with thyme, salt and pepper. In a large bowl, combine roasted mushrooms, onion, gruyere and thyme. Spread this mixture in the bottom of the pie shell in an even layer. Pour cream-egg mixture over the mushroom mixture, ensuring that all of the mushroom mixture is covered. Bake for 45 to 55 minutes, or until a knife inserted into the center of the quiche comes out clean. Serve warm or at room temperature.