Perfect Fajitas Every Time

Fajitas are a tasty and easy-to-make dish for those busy weeknights. They are a very versatile dish, and they are super easy to adapt for both meat lovers and vegetarians alike. There are a number of ingredients you can use to make the perfect fajita, but one that you won’t want to skimp on is the onion.
Onions are an essential ingredient in any fajita, but which onion should you use, and how should you prepare them? This guide will teach you about different types of onions commonly used while cooking fajitas. Perhaps most importantly, this guide will show you how to cut an oven for fajitas.
If you’ve wanted to learn how to cut an onion for fajitas, read on because this guide is for you!
The Layered Vegetable: The Onion
Onions are among the most common and well-known root vegetables in the entire world. Frequently used by many cultures in their cooking, onions can be used to add sweetness, savory flavor, or a satisfying crunch to any meal.
Onions can be eaten raw, but most varieties are almost always cooked; we’ll touch more on that later. Onions are nutritious, delicious, and come in several different varieties, any of which would make a great addition to any fajita. Let’s take a look at some popular types of onion.
Yellow Onions

Yellow onions are probably the most common and well-known variety. Versatile and sweet, these onions are easy to use in almost any dish. They have a strong scent and a thick yellow to yellow-brown outer skin. To use these onions, you’ll need to remove the outermost layer before cooking.
Once you remove the outer layer you can eat these raw, although it’s very common to cook these onions before eating. The longer you cook yellow onions, the more you draw out the natural sweetness of the onion.
Cook yellow onions over very low heat and let them “sweat”. Coat your frying pan with oil and add your onions. Over low heat, cover the pan and let the onions sit in the heat. Once they turn translucent, they’ll be ready to go.
While yellow onions won’t provide a crunchy finish, these onions will be sweet and flavorful. They’ll also add a serious burst of flavor to any fajitas. Yellow onions are one of the best onions you can possibly buy for fajitas. If you don’t end up using them for fajitas, you can use them to fry up some savory onion rings.
Red Onions

Red onions are an exciting choice for fajitas. They have a more intense flavor than yellow onions, although some of the stronger flavor can be cooked out. These onions can be eaten raw, so if you’re looking to cut down on prep time, these might be a good choice for your fajitas.
If you choose to eat your red onions raw, be aware that they have a very strong, spicy flavor! Of all the different onions you can buy, the red onions probably have the most powerful taste if not cooked. If you’re going to have these raw, be sure to cut them into thinner slices or even turn them into diced onions to moderate the spicy, strong flavors.
Similarly to the yellow onions, you’ll need to remove the thick outer layer before cooking or eating. You’ll know once you’ve gotten off the onion skin as it has a dry and almost rubbery feel, and the inner part of the onion should be wet and smooth.
Even if you don’t use red onions in your fajitas, you might want to pick them up to add to some homemade guacamole! Red onions are a perfect addition to guacamole and can be added raw and enjoyed right away!
White Onions

White onions are the most commonly used in Mexican cooking. They provide the perfect boost of flavor to take any fajita dish to the next level. While white onions can have a more subtle flavor than yellow, and certainly less than red, white onions will still provide a nice degree of sweetness when cooked.
While similar to red and yellow onions in that the white onions also have an outer layer, the outer layer of white onions is quite thin by comparison. While the thinner skin means that white onions are a bit faster to cut, they won’t last in a refrigerator as long. You may want to take that into account when you’re shopping for your meals.
These three onion varieties are far from the only ones you can buy, but they’re the most commonly used in fajitas and Mexican cooking. You can’t go wrong by choosing any of these varieties of onions, so pick the one that suits you most and get ready to prep your veggies for cooking!
Cutting Onions

It’s not just a myth; when you cut an onion there is an overwhelming chance that you’ll tear up or cry. This is because onions release a powerful chemical when punctured to ward off opportunistic, plant-eating rodents.
Not all onions will cause you to cry when you cut them, but you won’t really be able to tell until you cut into them. There isn’t that much you can do about it other than taking extra care while you’re cutting your onions. Take extra caution to ensure that you don’t accidentally cut your finger while your eyesight is compromised.
Thankfully, the onion-y assault on your senses won’t last more than a few minutes. Now that you know what to expect, let’s learn how to cut an onion for fajitas and get chopping.
Setup Your Cutting Space
You’ll need a cutting board, preferably with rubber edges for stability, and a sharp cutting or chopping knife. A chopping knife would be something like a kitchen cleaver, a long and heavy flat blade with no tip. A chopping knife is a good choice if you want to dice your onions, but if you’re looking for sliced onions, stick with a more traditional kitchen knife.
Make sure you have enough room to safely cut your onions. The prep shouldn’t take you more than 5-10 minutes based on the number of onions that you’re going to be cutting.
Begin Slicing Your Onion
As mentioned earlier, all onions have an inedible outer layer that you’ll have to remove prior to enjoying the distinct flavors of your onion. Start by turning your onion on its side and cut near the top and bottom of your onion. Cut a small chunk off each side to remove the root of the bulb and to make removing the skin easier.
Once you’ve cut off the top and bottom of the onion, the skin should peel right off. You’ll know when you’ve removed the skin properly since the rubbery outer layer will be entirely gone and all that will be left is the wet interior of your onion.
Now, sit the onion on the new flat bottom point you’ve created. At that point, you can slice the oven in half. Work on one half at a time. Take one of the halves and lay it flat on the wide half. Use your kitchen knife to cut across the onion at small intervals. Once you’re done you should have a pile of thin onion slices.
Now repeat this process on the other half of your onion until it’s been sliced down to the correct size. If you’re happy with this size, you’re done! Once you’ve finished, you can begin seasoning your vegetables and getting ready to cook your ingredients.
However, if you want to dice your onions, you’ll have a little bit more work to do. If you’re dicing your onions, take your pile of onion slices and angle your knife point side down on one end of the pile. Now begin cutting your onion slices into small cubed pieces. You’ll need to repeat this chopping action several times until the entire pile of onion has been cut down into the correct size.
You may need to re-angle your knife point as well; this is ok. Re-angle your knife however you need to, and keep one hand on the spine of your knife for safety at all times. Once you’ve sliced and diced, your onions are ready to be added to your favorite fajitas!
Perfect Fajitas Every Time
Your friends and family will marvel at your onion slicing and fajita cooking prowess. While chopping onions and vegetables might seem like a small part of the cooking process, it’s one of the most important.
If your vegetables and other ingredients are mismatched in terms of size, your dish won’t cook evenly and you’ll run the risk of burning some of the smaller cut ingredients while the larger cuts turn out undercooked. Learning how to cut an onion for fajitas won’t take you that much time, and it will go a long way in making sure that your dinners turn out great every time!