2cupshalf-and-halfhalf and half is 12% - light cream 20% works too
freshly ground salt and pepper
Preheat oven to 350 degrees and grease an 8" or 9" pie or tart dish.
In a large frying pan, add the olive oil, and saute the mushrooms on medium/medium-high heat until softened, approximately 5 minutes. Add butter, shallots, and thyme, and saute for another 5 minutes. The goal is to extract most of the moisture from the mushrooms, so if there's any moisture still in the pan, let it simmer off for another few minutes. Set aside.
In a blender, add the half-and-half, eggs, pinch of nutmeg, and a few grinds of salt and pepper. Blend on high until frothy. (Alternatively, you can vigorously whisk these ingredients together in a large bowl.)
To arrange the quiche, spoon half of the mushroom mixture into the prepared pie/tart dish. Pour half the blended custard mixture on top, and sprinkle with half of the cheese. Then repeat: add half of the mushrooms, pour the rest of the custard mixture, and finish with sprinkling the rest of the cheese.
Bake the quiche for 40-45 minutes, or until the eggs are set and the middle is still slightly jiggly. Let cool for 10 minutes before serving.
If you don't extract most of the moisture from the mushrooms, you will end up with a quiche that has a bit of excess liquid in the dish. Still tasty, but less attractive when slicing!