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Summer calls for colorful dinners made in no time at all. These healthy and easy Beef Fajitas are perfect for that! Delicious, filling, and ready in less than 20 minutes.

Meat, peppers, and sliced avocado separated on a plate for these easy beef fajitas

When you’re looking for a quick, healthy weeknight dinner that is still satisfying and full of flavor, these easy beef fajitas are absolutely perfect!

You need less than 20 minutes for this dish to come together. It’s super tasty and a great blend of vegetable carbs, protein, and healthy fat.

It’s also a gorgeous way to add some colors to your plate!

How to make easy beef fajitas

This dish is as easy to make as chopping your ingredients and then frying them up!

Step 1: Heat a cast-iron skillet over medium heat.

Step 2: Wash and deseed bell peppers, then slice them into 1/4″ (0.5 cm) thick long stripes. Set aside.

Step 3: Peel and slice the red onion. Set aside.

Step 4: Once the skillet is hot, add a splash of oil. When the oil is hot, cook the beef stir-fry strips in 2-3 batches. Make sure the strips don’t touch each other.

Step 5: Salt and pepper each beef stir-fry batch generously in the pan. Cook for about 1 minute per side, then set aside on a plate and cover to keep warm.

Step 6: Once all the beef is cooked and set aside, add sliced onions and bell peppers to the remaining meat juice. Season with cumin and chili powder, then stir-fry until desired consistency.

Step 7: Transfer the veggies and beef stir-fry strips to a plate and serve with sliced avocado, a drizzle of lemon juice, and a sprinkle of fresh cilantro.

See how simple that was? Once you make this dish once, it’s going to quickly become a weeknight favorite!

How to fry beef fajita strips

There is a little bit of an art to making sure your beef fajita strips stay nice and juicy.

The number one mistake most people make is adding the beef straight from the fridge. If the beef is still cold, it will lower the temperature in the pan, which makes the strips boil instead of fry.

Instead of doing that, take the strips out of the fridge 30 minutes before frying so they can come to room temperature. This gives you the best frying results.

The next mistake is adding all the strips to the pan at once. Instead, fry them in several batches if you are making a lot. They get a more even frying if they don’t touch each other in the pan. It only takes about 3 minutes to cook each batch, so the overall time doesn’t get much longer by splitting the strips into batches.

Finally, you want the pan to be SMOKING hot. Wait at least a few minutes for the pan and oil to properly heat up before adding the beef stir-fry strips.

Overhead shot of the cooked beef, veggies, and avocado on a plate

Best veggies for fajitas

In my opinion, bell peppers are the perfect veggie for stir-frying. They are a little bit sweet while still being savory, and they keep their firm consistency when heated. Combined with onion, they form the basis of a lot of stir-fry recipes.

Bell peppers are also great from a nutritional standpoint. They are loaded with vitamin C and are high in other vitamins and minerals as well.

When cooking the bell peppers, the amount of time you cook them will depend on how you like the texture. I like them still crunchy, so I only stir-fry for about 5 minutes. If you like your vegetables softer, stir-fry for a little longer.

Storage

If you find yourself with any leftovers, they can be stored in an airtight container in the refrigerator for 3-4 days.

If possible, store just the beef and veggies together without the avocado, as sliced avocado will quickly oxidize and turn brown and mushy.

Want to do a little meal-prepping for the week? The veggies will get soft in the fridge once cooked, but cooked beef stir-fry strips will keep very well!

To get some of the prep out of the way, fry the beef fajita strips ahead of time, then cook the veggies and slice the avocado once you’re ready to serve.

Other easy and healthy dinner recipes

Easy, healthy, and tasty dinner recipes never get old! Here are a few more favorites that you can whip up on busy weeknights:

For even more healthy recipes, check out my roundup of the best healthy dinner recipes for diabetics.

When you’ve tried this dish, please don’t forget to let me know how you liked it and rate the recipe in the comments below!

Healthy & Easy Beef Fajitas You Can Make in 15 Minutes

4.15 from 27 votes
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Summer calls for colorful dinners made in no time at all. These healthy and easy Beef Fajitas are perfect for that! Delicious, filling, and ready in less than 20 minutes.
Author: Lorena Grater
Prep Time: 5 minutes
Cook Time: 10 minutes
Total Time: 15 minutes
Servings: 4

Ingredients 

  • 1 lbs. beef stir-fry strips
  • 1 medium red onion
  • 1 red bell pepper
  • 1 yellow bell pepper
  • ½ teaspoon cumin
  • ½ teaspoon chilli powder
  • splash of oil
  • Salt
  • Pepper
  • Juice of half a lime
  • Freshly chopped cilantro, (also called coriander)
  • 1 avocado

Instructions

  • Heat a cast-iron skillet over medium heat.
  • Wash and deseed bell peppers, then slice them into 1/4" (0.5 cm) thick long stripes. Set aside.
  • Peel and slice red onion. Set aside.
  • Once skillet is hot, add a splash of oil. When the oil is hot, add stir-fry strips in 2-3 batches. Make sure the strips don't touch each other.
  • Salt and pepper each beef stir-fry batch generously in the pan. Cook for about 1 minute per side, then set aside on a plate and cover to keep warm.
  • Once all the beef is cooked and set aside, add sliced onions and bell peppers to the remaining meat juice. Season with cumin and chili powder, then stir-fry until desired consistency.
  • Transfer the veggies and beef stir-fry strips to a plate and serve with sliced avocado, a drizzle of lemon juice, and a sprinkle of fresh cilantro.

Notes

This recipe is for 4 servings of beef fajitas.
Take the beef stir-fry strips out of the refrigerator 30 minutes before cooking them. By letting them come to room temperature, they won’t lower the temperature of the pan, which will give you better frying results.
Also, cook the beef in batches, ensuring none of the strips are touching each other. This makes sure each piece is evenly fried.
Make sure the pan is smoking hot before adding the beef strips.
When cooking bell peppers, cook for about 5 minutes if you like a little crunch or longer if you like them a bit softer.
Leftovers can be stored in an airtight container in the refrigerator for 3-4 days, but they are best stored without the avocado, as sliced avocado will quickly oxidize and turn brown and mushy.
If meal-prepping, you can cook the beef stir-fry strips ahead of time and store in the refrigerator. Then, when you’re ready to eat, cut and fry the veggies and slice the avocado before serving.

Nutrition Info Per Serving

Nutrition Facts
Healthy & Easy Beef Fajitas You Can Make in 15 Minutes
Amount per Serving
Calories
336
% Daily Value*
Fat
 
16.8
g
26
%
Saturated Fat
 
5.2
g
26
%
Trans Fat
 
0
g
Polyunsaturated Fat
 
1.1
g
Monounsaturated Fat
 
6
g
Cholesterol
 
86
mg
29
%
Sodium
 
67
mg
3
%
Potassium
 
375
mg
11
%
Carbohydrates
 
10.6
g
4
%
Fiber
 
4.4
g
18
%
Sugar
 
4.6
g
5
%
Protein
 
30.5
g
61
%
Vitamin A
 
2400
IU
48
%
Net carbs
 
6.2
g
* Percent Daily Values are based on a 2000 calorie diet.