This Mushroom, Swiss, & Onion Quiche is a brunch recipe you need to try! Pre-cooking the veggies is our secret trick-and did we mention this is vegetarian? 

THE INGREDIENTS: 

Pie Crust: Whether you use homemade pie crust, store-bought pie crust, or even go without it, this quiche will turn out delicious! This recipe requires just one pie crust that will go on the bottom of the pan. It provides a wonderful crunch which goes very well with the smooth texture of the egg mixture (and let’s be real, we all love some carbs). 

Eggs: The star of our show! It’s not a quiche without some eggs. Eggs have two important parts, the yolk and the egg white. The yolk is where the dense texture of baked goods comes from. Too many egg yolks makes a quiche overly dense. So, if you up the eggs in this recipe, you risk losing that smooth texture that the current egg to dairy ratio in this recipe gives. We already have a pretty high ratio, as the standard is 1 egg per ½ a cup of added dairy. This means that if you like your quiche even more custardy, you should be able to reduce it to a minimum of 2 eggs, but we believe it is best with 4 eggs. 

Cream: Our Tomato, Zucchini, and Basil Quiche makes use of sour cream and milk, perfect for when you have part of a tub of sour cream to be used up in your fridge. However, we don’t always have sour cream (or milk…) on hand! So, we decided to create another quiche recipe for such emergencies. Our goal is to add as much dairy fat as we can into a quiche for that rich, soft texture.

Don’t have cream (or enough cream) on hand? That’s ok, you can still make these substitutions: ¾ cup milk (the higher fat content, the better!) and ¼ cup melted butter, ½ milk ½ sour cream, half and half (either actual half and half or ½ cup cream and ½ cup milk). Keep in mind that although all of these substitutions work, each comes with a slightly different texture. All of them are soft, but we truly enjoy the texture that comes with adding exactly 1 cup of heavy cream. 

White Mushrooms: We wanted to keep it classic, and white mushrooms are the classic quiche mushroom. It may seem like a lot to add 16 ounces of mushrooms into a quiche-but trust us, it’s not too much! There is still plenty of eggy quiche custard with each mushroomy bite. Don’t have white mushrooms on hand? Here are our recommendations: cremini (brown) mushrooms, shiitake mushrooms, or even sliced up portabella mushrooms. 

Yellow Onions: Why yellow onions? Why not white onions? Well, the answer is…we use what we have on hand! Whether you use shallots (although the flavor will be a bit weaker and you will need to use more than 2, more like 4), white onions, yellow onions, or sweet onions, you should be happy with this Mushroom, Swiss, & Onion Quiche! Green onions and red onions do not fit as well here, so we can’t say we recommend them.

Although adding dried minced onion and onion powder may be easier, hold on! First, hear about the method to our madness. When you spend the time to cook the onion down in butter and spices, it gets a very rich flavor that is not easily replicated just by adding onion powder, or even adding raw fresh onion, to the quiche. All of that being said, use what you have on hand! We would recommend a crazy 2 tablespoons of onion powder. Don’t be afraid to go heavy on spice, it is where the flavor is! However, also eat what you are comfortable with and reduce this as needed. If you are using dried minced onion, we recommend adding it with the minced garlic to the cooking mushrooms. How much, you ask? Around ¼ cup! Again, reduce as desired.  

Swiss Cheese: Swiss and mushrooms are a pair, just think of how many sandwiches with mushrooms also have swiss! We use 1 cup of shredded swiss cheese in this recipe, also known as 4 ounces, also known as 4.5 slices of swiss cheese. The cheese flavor is there without being dominating, so if you are a cheese lover, you could even up the swiss to 2 cups shredded! Again, that would be 8 ounces or 9 slices of swiss cheese. It should not affect the texture or make the quiche seem too overloaded, in our opinion. As much as we love cheddar cheese, it just isn’t a good substitute here. If you don’t have swiss cheese on hand, try reaching for these other cheeses instead: goat cheese, mozzarella cheese, provolone cheese, parmesan cheese, feta cheese, brie cheese, havarti cheese, gruyere cheese, or gouda cheese. 

Garlic Cloves: Although we’d apologize for how many of our recipes contain garlic, we have to get you to admit it just goes so well with so many different things! By adding the garlic to the cooking onion and mushrooms, they have a stronger depth of flavor that really stands out in this Mushroom, Swiss, and Onion Quiche. We try not to go overboard on the garlic in this recipe because we figure you don’t want to start your morning off with too much garlic breath! Although, when we say 2 cloves of garlic, we mean 2 large cloves of garlic. Don’t have garlic? That’s okay, use ½ a teaspoon of garlic powder. ¼ teaspoon should go into the cooking onions and ¼ teaspoon should go into the cooking mushrooms. 

Butter: We hope it has been established by now that this quiche is full of dairy fat-and we have no regrets! Although you can reach for neutral oil instead to cook these veggies, we find that their buttery flavor really stands out in this quiche recipe. 

Salt: A necessity! Salt keeps your meal from tasting “flat” or missing that savory flavor. However, everyone has their own preferences for salt, so adjust to your liking. 

Freshly Cracked Black Pepper: When you eat eggs, don’t you normally add a little salt and a little black pepper? Well, with a quiche, it’s not any different! Since we don’t have a blend of many different spices in this recipe, we like to use freshly cracked black pepper. Why? It stands out so much more and has a flavor that is almost completely different from pre-ground black pepper. Go as heavy or as light as you want, this is your quiche! 

KEY INFORMATION: 

Pre-Baking Pie Crust: If you don’t pre-bake your pie crust, you risk a delicious meal ruined by soggy, undercooked dough. Once your pie crust is in your pan, we recommend blind-baking it. We personally go for 425 F and have found that it takes about 10 minutes. If you don’t want to just consider the time, however, wait until the edges start to have a golden-brown tint! Before pre-baking, you can also poke your dough with a fork to prevent your dough from puffing up. 

Don’t Add Everything at Once!: We’ve all been there. We read the ingredients list and figure we can wing the rest. As small as it might seem, it is really important to mix the eggs and cream together before adding the mix-ins. Otherwise it gets very difficult to evenly distribute the egg mixture throughout the quiche. In addition to that, if you don’t read the ingredients, you won’t know to pre-cook the mushrooms and onions! Talk about a disaster. 

Why Pre-Cook Mushrooms and Onions Before Adding Them to Quiche? For several reasons, in fact! The first reason is that it means we can add even more mushrooms and onions to our Mushroom, Swiss, & Onion Quiche. When you cook both mushrooms and onions, they “cook down” or reduce in size. So, the mix-ins aren’t sparse in this recipe.

The second reason is that mushrooms and onions are watery and release liquid while cooking. That may be a good thing for your meatloaf, but it’s actually a bad thing for this quiche. Here, the texture is already moist enough, and we don’t want to make it soggy.

The final reason is that it gives this quiche a much better flavor than if you were to add the vegetables raw. What tastes better to you-raw onion or onions cooked down in butter, garlic, salt, and pepper? If cooked onions taste better for other recipes, it is no surprise it tastes better in this quiche, too. 

Good Ways to Use Up Veggies You Already Have: Recipes can almost always be tweaked to use up what you already have. Nearly any vegetable will go in a quiche, just take into consideration the amount and how wet are the vegetables you are adding. Try out our Tomato, Zucchini and Basil Quiche if you have those ingredients on hand. Reach for the broccoli or cauliflower and make a quiche with some cheddar mixed in! Bell pepper? Yeah! Asparagus? Why not? Spinach, come on in! We’ve even had some good quiches with diced potatoes added. Corn would be cool. Leeks wouldn’t be a let down. We haven’t tried peas but sometimes we wonder if that might be “weird but good”, too. Yellow squash, tomatillos, sweet potatoes…honestly almost any vegetable goes in a quiche if you try hard enough. 

What Goes With Quiche?: What main meal doesn’t benefit from some sides? When we’re feeling healthy, we like to pair our quiche with fresh fruit (those tiny mandarins are the best!) or even a side salad. Otherwise, breakfast potatoes or some form of toast are staples around here. If you need a bit more protein to balance your carbs, go ahead and pair it with some breakfast meats: think turkey bacon or some kind of sausage. 

Crustless Quiche: Whether you don’t like the flavor of pie crust or you just want to lower your carb intake for this meal, crustless quiche is the way to go! All you have to do is skip the pie crust preparation steps in this recipe and you’re all set. No other alterations needed. 

Does Quiche Taste “eggy”? Honestly, no! The eggs combine with all of the other ingredients to have a more custardy, unique flavor. If you don’t want the flavor of eggs to be overly apparent, don’t let yourself think this recipe isn’t for you! If you are looking for that distinct “eggy” flavor, however, we recommend going for a frittata. There is far less dairy per each egg. 

Is Quiche Healthy? Everyone has different nutritional needs! However, with the presence of protein and vegetables in this Mushroom, Swiss, & Onion Quiche, we’d say this is a safe option if you’re looking for clean eating choices. The presence of cheese, butter, and cream means that quiche is not a low-fat meal.