Bacon and Mushroom Quiche with Caramelized Onions

This bacon and mushroom quiche is loaded with thick-cut bacon, caramelized onions, and asiago cheese for the perfect savory brunch dish.

If you love this quiche recipe, I bet you'll also love our Steak Omelette, Tex-Mex Dutch Baby with Chorizo, and Ham and Potato Frittata!

I love a good quiche, and this bacon and mushroom quiche just might be my best creation yet! It's packed with savory flavors and hearty enough for breakfast or brunch.

The star of the show here is those caramelized onions. Cooking them down to a jammy consistency takes a bit of time, but it's so worth it! The result is a naturally sweet onion jam that goes perfectly with the earthy mushrooms.

Ingredients Needed

• Thick-cut bacon — Six slices is all you need, and the thick cut gives you those hearty, meaty bites throughout the quiche. You'll render the fat to cook the veggies, so nothing goes to waste!
• Yellow onion — This gets caramelized low and slow until it's sweet and jammy. You could swap in a white or sweet onion if that's what you've got.
• Baby bella mushrooms — Also called cremini mushrooms, these have a deeper, earthier flavor than white button mushrooms. Either works though!
• Asiago cheese — I love the nutty, sharp flavor of Asiago, but Swiss, Gruyere, or white cheddar would all be delicious here. Use whatever cheese you prefer, as long as it grates well.
• Eggs — The base of any good quiche! Five eggs creates that perfect custardy texture. Large is standard.
• Whole milk and heavy cream — This combo makes the filling rich and creamy without being over-the-top heavy.
• Fresh thyme — Totally optional, but it adds a great flavor the mushrooms and bacon.
• Pie crust — I'm all about using store-bought refrigerated pie crust for this. No shame in making life easier!

For a full list of ingredients and instructions, check the recipe card below.

How to Make Bacon and Mushroom Quiche with Caramelized Onions

1. Cook the bacon: Cut your bacon into half-inch strips and cook in a large skillet over medium-high heat until crispy, about 10 minutes. Transfer to a paper towel-lined plate.
2. Caramelize the onions: Leave about a tablespoon of bacon grease in the pan. Add the onions and cook for 5 minutes, then lower the heat to medium-low and cook for 25 minutes, stirring often. If the pan gets dry, add a splash of water.
3. Add the mushrooms: Toss the mushrooms in with the onions, add a pinch of salt, and cook for 10 minutes until tender. Let everything cool for 10-15 minutes.
4. Make the filling: Preheat your oven to 350 degrees. Whisk together the eggs, milk, and cream. Fold in the cheese, thyme, bacon, mushrooms, and onions. Be sure to drain any liquid off the mushrooms.
5. Bake: Pour the filling into a pie crust-lined dish and bake for 40-50 minutes, until the center is set. Let cool for 10 minutes before slicing.

Sara's Expert Tips

• Don't rush the onions. If you notice the pan beginning to dry out while cooking down the onions, add a splash of water. This will help bring them to the jammy consistency you want instead of burning.
• Let everything cool. Before mixing the bacon, mushrooms, and onions into the egg mixture, give them time to cool down. Hot ingredients can start cooking the eggs prematurely. You'll also want to drain any excess liquid off the cooled mushrooms.
• Check for doneness. The quiche is ready when the center is just set—it should have a slight jiggle but not be liquidy. If the crust starts browning too quickly, cover the edges with foil.
• Be patient before slicing. That 10-minute cooling time isn't optional! It lets the filling set up so you get clean slices instead of a runny mess.

Storage Information

This quiche will keep in an airtight container in the refrigerator for up to 4 days.

You can reheat individual slices in the microwave for about a minute, or warm the whole thing in a 325-degree oven for 15-20 minutes. It can also be frozen for up to 3 months—just thaw it overnight in the fridge before reheating.

More Recipes for Bacon and Mushroom Lovers

• Bacon Bourbon Jam
• Steak Omelette with Peppers, Onions, and Mushrooms
• Peppered Bacon (Glazed and Oven Baked)
• The Best Sauteed Mushrooms and Onions for Steak

📖 Recipe