1large onionor 2 medium, sliced into thin half moons
red winefor deglazing (optional)
1teaspoonfreshly ground black pepper
2cupsgrated quality cheddar
1cupgrated melty cheesesuch as fontina
1cupgrated Parmigiano reggiano
caramelize the onions
Place the bacon strips in a cold frying pan or wide saute pan - you'll need a lid or a cover of some sort (such as foil) - with enough water to barely cover the surface. (It's perfectly okay to cut the bacon into halves or thirds, so they fit in one layer in the pan.) Turn the heat to medium-low, and let the bacon cook, turning every now and then, until both sides are done to the crispness you prefer. Remove the bacon to a plate lined with paper towels, to soak up the excess grease. Drain all but one tablespoon of bacon fat from the pan and return to the heat (still on medium-low).
Add the sliced onions, and stir well to coat with the bacon fat. If there are brown bacon bits stuck to the bottom of the pan, deglaze with a few short pours of red wine. Cover the pan and cook, stirring occasionally, for 1 to 1 1/2 hours. Properly caramelized onions will soften and reduce over time, starting off pale beige and slowly turning a deep golden brown. So as to not drag things out eternally, you can remove the lid after an hour. When the onions are a deep golden brown, remove from the heat and let rest.
cook the spaghetti
When the onions are starting brown up, preheat the oven to 425°F and butter or spray a 9" springform pan.
Cook the spaghetti to al dente, according to package directions. Drain.
While the spaghetti cooks, whisk the eggs, milk, and black pepper together in a large bowl, then mix in about 3/4ths of each of the cheeses, reserving the rest. Stir in the cooked spaghetti and the caramelized onions. Crumble the bacon and stir that in as well.
Snuggle the springform pan into a square of foil, bringing the edges up and covering the bottom seam of the pan. (This will keep your oven clean!) If you've been caught without foil, place the pan on a rimmed baking sheet.
Pour the spaghetti mixture into the prepared springform pan and sprinkle the remaining cheeses over the top. A grind or two of pepper would not be out of line here.
Bake for 35 to 40 minutes. Turn on the broiler, and place the pan about 8" from the broiler unit. Let the cheese brown, then remove.
Let the spaghetti pie rest for 15 minutes, then use a thin bladed knife to cut around the edge of the pan. Remove the springform ring. Slice, and serve.
Three Cheese Caramelized Onion Spaghetti Pie was originally published on https://soupaddict.com/caramelized-onion-spaghetti-pie/