Best Sheet Pan Fajitas with Steak (Whole30, Low Carb)
A quick and easy sheet pan fajitas recipe with super tender steak and a quick guacamole. With flank steak, peppers, and onions, this healthy Mexican recipe is a one-pan dinner. Whole30, paleo, low carb.
1largered onionhalved and sliced into ¼"-wide pieces
1poundthinly-sliced flank steak or “fajita” steak
For the Guacamole
3largeavocadospeeled, pit removed
¼cuppico de gallo or fresh salsastore-bought or make your own
1tablespoonlime juicejuice from half of one lime
1teaspoonsalt
Suggested for Serving (All Optional)
salsa
lime wedges
fresh cilantrochopped
red onionchopped
radishessliced
lettuce cups
tortillasif not on Whole30
Instructions
Place oven racks so that oven is evenly divided into thirds. Place empty baking sheet on top oven rack and preheat broiler on High.
For the Fajita Veggies
In small bowl, mix together avocado oil, garlic, chili powder, lime juice, oregano, cumin, and salt.
Place sliced peppers and onions in large bowl. Pour half of avocado oil mixture over veggies and toss well to coat.
Carefully and quickly, remove baking sheet from oven and transfer marinated peppers and onion to baking sheet. Return baking sheet to oven and cook on top rack under broiler for 7 minutes, or until veggies begin to soften and brown.
For the Guacamole
While peppers and onions are in oven, make guacamole by adding all guacamole ingredients to small bowl. Mash to desired consistency and taste, adding more salt as desired. Set aside or chill until ready to serve.
For the Fajita Steak
Place sliced steak in large bowl that was used for peppers and onions. Top with remaining avocado oil marinade and toss well to coat.
After peppers and onions have cooked 7 minutes (or until softened and browned), carefully and quickly remove baking sheet from oven. Use tongs to rearrange pan, creating space between peppers and onions. Place marinated steak in spaces in one flat layer, being careful not to overlap or overcrowd.
Return baking sheet to oven. Cook 4 minutes, or until steak is uniformly browned on top. Steak will likely show medium-rare temperature on underside, not on top, so carefully use tongs to flip steak and check doneness. Add additional time as needed to reach desired doneness.
To Serve
Carefully remove baking sheet from oven. Garnish with guacamole and toppings as desired. Serve fajita vegetables and steak as-is, in burrito bowls with cauliflower rice, or with lettuce cups or tortillas (if not on Whole30).
Notes
For even more flavor to your steak, marinate it in half of the avocado oil mixture in the fridge for up to 12 hours before cooking. Just take it out of the fridge about 30 minutes before you cook it.
Make sure to prep all of your ingredients before starting. This recipe moves pretty quickly once you get going, so there's not time to stop and chop things halfway through!