Caramelized Onion Quiche - Test 3

 https://www.simplyrecipes.com/recipes/caramelized_onion_quiche/

1 - Made once, and it was highly acclaimed. I can't remember if I switched out the nutmeg for the mustard, or if I kept one and discarded the other.

2 - Served it to a party of 12 and they liked it!

3 - Rocked it again. The onions cooked a little faster but it does take a long time. I altered the writing a bit here to make the steps clearer.

1 blind-baked pie crust, completely cooled

2 Tbsps mild veg oil

2-3 (about 1lb) large onions, French-cut (teenie tiny wedges)

Salt and freshly ground pepper

2 tsps balsamic vinegar

3 large eggs

1 cup coffee cream OR ½ cup heavy cream + ½ cup milk

1 tsp Dijon mustard 

Pinch nutmeg

6 ounces Gruyère cheese, grated (1 1/2 cups)

1. The onions will take about an hour to cook on the stovetop before they are ready to go into the quiche. So timing-wise, get started on the onions once you've put the crust in the freezer to chill before pre-baking.
2. There are 3 steps to cooking the onion: softening, caramelizing, and deglazing.
3. Softening the onion: heat the oil in a large, heavy-bottomed sauté pan on medium heat. Add the onions and sprinkle a little salt over them. Cook, stirring occasionally for 10 minutes, until the onions have softened and are translucent. 
4. Caramelizing the onion: reduce the heat to medium low and cook for an additional 30 to 40 minutes, stirring occasionally, until the onions are well browned and very soft.
5. Deglazing the onion: once the onions are well browned, add the balsamic vinegar to the browned onion and cook for 10 minutes more, until onions are completely caramelized. Remove from heat.
6. Pre-heat the oven to 375°F
7. Sprinkle half the cheese evenly over the bottom of the baked crust. Spread the onions over the cheese and then top with remaining cheese.
8. In a medium bowl, whisk together milk, cream, eggs and mustard. Season with nutmeg, salt, and pepper. Pour over the tart.
9. Reduce the oven temperature to the 350°F, and bake the pie until just set in the center, 30 to 35 minutes. Cool on a wire rack for about 10-15 minutes before slicing.
10. To keep the quiche warm, cover it with aluminum foil and bake it in a preheated oven at 200-250F.