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Best sheet pan fajitas with steak and peppers on a sheet pan with lime slices and guacamole off to the side

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.

Course Main Course
Cuisine Mexican
Keyword fajitas, sheet pan, steak
Prep Time 5 minutes
Cook Time 11 minutes
Total Time 16 minutes
Servings 4 people
Calories 568 kcal


Sheet Pan Steak Fajitas

  • 3 large bell peppers preferably 1 red, 1 orange, 1 yellow, seeded and sliced into 1/2" strips
  • 1 large red onion halved and sliced into 1/4" pieces
  • 1/4 cup avocado oil
  • 2-3 cloves garlic minced or pressed
  • 2 teaspoons chili powder
  • juice of 1/2 lime
  • 1 teaspoon oregano
  • 1 teaspoon ground cumin
  • 2 teaspoons salt
  • 1 lb. thinly sliced flank steak or “fajita” steak
  • lettuce cups or tortillas


  • 3 avocados peeled and seeded
  • 1/4 cup pico de gallo or fresh salsa
  • juice of 1 lime
  • 1 teaspoon salt

To Serve

  • Fresh salsa
  • Limes to serve
  • Fresh chopped cilantro
  • Fresh chopped red onion
  • Radishes


  1. Prepare all ingredients before cooking: slice peppers, slice steak, peel and seed avocados, chop garlic, etc. Preheat your broiler with oven racks in thirds; place baking sheet on top rack.
  2. In a small bowl, stir together avocado oil, garlic, seasonings, and salt. Put peppers and onions in a large bowl and pour half of garlic-seasoning mixture over; toss well to coat. Carefully but quickly remove baking pan and scatter peppers and onions over. Return to oven and cook for 7 minutes, or until beginning to soften and brown.
  3. While peppers and onions cook, make guacamole. Combine avocado meat, lime juice, fresh salsa, and salt; mash to desired consistency and season with more salt, if desired.
  4. Place sliced steak in the large bowl and pour remaining garlic-seasoning over; toss well to coat. After peppers and onions are cooked, quickly but carefully remove baking pan from oven and use a spatula to make a space between peppers. Place steak in a single layer, being careful not to crowd if possible. Return to oven and cook 4 minutes or until uniformly brown on top and medium rare. Steak will likely show medium-rare temperature on underside; it will not show on top.
  5. Remove pan from oven and serve in tortillas or lettuce cups with guacamole, more fresh salsa, and garnish with fresh chopped cilantro and/or red onion, if desired.

Recipe Notes

You can marinate your steak ahead of time if you prefer; this will result in an even more flavorful and tender steak. Simply coat your sliced steak in half the garlic-seasoning mixture and chill; marinate for up to 12 hours. Take out of fridge about 30 minutes before cooking.

Nutrition Facts
Best Sheet Pan Fajitas with Steak (Whole30, Low Carb)
Amount Per Serving
Calories 568 Calories from Fat 378
% Daily Value*
Fat 42g65%
Saturated Fat 7g44%
Cholesterol 68mg23%
Sodium 1951mg85%
Potassium 1421mg41%
Carbohydrates 23g8%
Fiber 13g54%
Sugar 6g7%
Protein 29g58%
Vitamin A 3390IU68%
Vitamin C 131.8mg160%
Calcium 78mg8%
Iron 3.8mg21%
* Percent Daily Values are based on a 2000 calorie diet.