Using a wooden spoon, mix just until combined, but crumbly.
Turn out on floured surface and press the dough together, folding it over on itself several times. Doing this will make it smooth. This isn’t like typical pie dough.
Flouring your rolling pin, roll this dough out to 12” round.
Rolling the dough gently around the rolling pin, place the dough into a 10 or 11” round tart pan with a removable bottom.
Press the dough along the sides and bottom, using a knife to remove the excess overhang.
Cover with plastic wrap and refrigerate while making the filling.
Quiche
Preheat oven to 375F placing a rack on the lowest rung.
In a medium (12” non-stick skillet) over medium heat cook the bacon until crispy. ~5-8 minutes
Remove the bacon from the pan and place on a paper towel.
In the pan with the bacon grease, add in the onions and mushrooms.
Cook for 2 minutes then add 1/2 teaspoon salt and pepper.
Sauté until the onions are soft and the mushrooms have a slight golden brown color. ~5 minutes.
Add in the spinach all at once and cover.
Cook for 5 minutes and remove the lid.
Stir the mixture around and remove from the heat. The mushrooms should be soft and reduced considerably.
Transfer the mixture to a medium sized bowl.
Add in the bacon to the bowl and stir.
Next, add in the cream and cheese stirring to combine.
Add in the eggs and with a sturdy spoon, beat to combine.
Add in the milk, nutmeg and remaining salt and pepper.
Remove the pan from the fridge and remove the plastic wrap.
Place the pan on a baking sheet (this will help if it spills over or leaks).
Spoon in the bacon spinach mixture into the dough and using the back of a spoon, smooth it out. The mixture should be no less than 1/4” from the top of the crust/pan.
Place the tray on the lowest rack and bake for 35-40 minutes or until the edges of the tart of golden brown and the middle barely jiggles. It will continue to set while it cools.