Preheat oven to 350 degrees F.
Roll out the pie crust on a lightly floured surface to fit a deep 9 or 10-inch pie pan. Place the pastry in the pie pan and crimp edges decoratively. Refrigerate at least 30 minutes, then line with aluminum foil. Fill with pie weights and bake for 12 to 15 minutes, or until lightly golden around the edges. Remove foil and pie weights, and return to the oven for 3 to 5 minutes. Remove from the oven and place crust on a wire rack to cool.
Set a 12-inch saute pan over medium heat, and add the butter and olive oil and once the butter is melted, add the yellow onions, red onions, and leeks to the pan and cook, stirring occasionally, until the onions and leeks are wilted, and lightly caramelized, about 8 minutes. Add the ham, mushrooms, thyme, and garlic to the pan and season with 1 teaspoon of the salt and the pepper. Cook the onions, ham and mushrooms, stirring occasionally, until most of the moisture has cooked out of the mushrooms and they are caramelized, 8 to 10 minutes. Remove the pan from the heat and allow the onions, ham and mushrooms to cool for 10 minutes before placing in the pie crust.
In a medium bowl, combine the heavy cream, eggs, remaining 1/4 teaspoon salt and the nutmeg and whisk until just combined. Stir 1 1/2 ounces of the grated cheese, then pour the cream mixture over the onion mixture, and sprinkle the remaining cheese over top. Place the pie tin on a sheet pan and place in the oven. Bake until golden brown, and the custard has set, 35 to 40 minutes. Be sure to rotate the sheet pan after 15 to 20 minutes to ensure even browning.
Yield:1 (9 or 10-inch) pie
In the bowl of a food processor combine flour, Essence, salt, and butter and process until mixture resembles coarse crumbs. While the motor is running, add water in increments until dough just comes together to form a ball. Transfer dough to a lightly floured surface and shape into a flat disk. Refrigerate overnight or at least 1 hour.
Remove from refrigerator and roll out on a lightly floured surface to desired shape and thickness.
Yield: 8 servings
Combine all ingredients thoroughly.
Yield: 2/3 cup

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Nutrition Facts

Per Serving Per 100 g

Amount Per 1 Serving
Calories	6049.85 Kcal (25330 kJ)
Calories from fat	4697.98 Kcal
		% Daily Value*
Total Fat	522g	803%
Cholesterol	2418.09mg	806%
Sodium	20337.8mg	847%
Potassium	3572.71mg	76%
Total Carbs	236.91g	79%
Sugars	24.02g	96%
Dietary Fiber	32.26g	129%
Protein	135.12g	270%
Vitamin C	37mg	62%
Vitamin A	5.3mg	175%
Iron	28mg	155%
Calcium	1518mg	152%

Amount Per 100 g
Calories	279.8 Kcal (1171 kJ)
Calories from fat	217.28 Kcal
		% Daily Value*
Total Fat	24.14g	803%
Cholesterol	111.84mg	806%
Sodium	940.61mg	847%
Potassium	165.24mg	76%
Total Carbs	10.96g	79%
Sugars	1.11g	96%
Dietary Fiber	1.49g	129%
Protein	6.25g	270%
Vitamin C	1.7mg	62%
Vitamin A	0.2mg	175%
Iron	1.3mg	155%
Calcium	70.2mg	152%

* Percent Daily Values are based on a 2000 calorie diet. Your daily values may be higher or lower depending on your calorie needs.
Find out how many calories should you eat.