Smoky Mushroom and Black Bean Fajitas

Deborah Rock
Deborah Rock
Published: July 28, 2026
Categories: Vegetables, Mexican, Vegetarian
Tags: Vegetarian, Weeknight Dinner, Skillet, Mushrooms, Mexican-Inspired, Black Beans, Fajitas

Mushroom Black Bean Fajitas

Sizzling portobello mushrooms, sweet peppers, and black beans fill warm tortillas with smoky flavor, finished with lime crema and quick-pickled red onion.

Prep Time:25 minCook Time:20 minTotal Time:45 minServings:4Difficulty:Easy

These fajitas build their savory center around portobello mushrooms and black beans rather than a meat substitute. A hot skillet gives the mushrooms browned edges while keeping the peppers crisp-tender, so the filling stays juicy without becoming watery.

Smoked paprika, cumin, oregano, and garlic provide a warm, earthy seasoning. The spice mixture is added after the vegetables have browned, which keeps it from scorching and lets it bloom briefly in the oil before lime juice loosens the flavorful bits from the pan.

Quick-pickled red onion supplies brightness while a simple lime crema cools the smoky filling. Both toppings can be prepared while the vegetables cook, making this a practical dinner with plenty of contrasting color and texture.

Serve the components at the table and let everyone assemble their own tortillas. Keep the filling hot and the tortillas wrapped in a clean towel; small additions of avocado, cilantro, and pickled onion make each fajita fresh without overwhelming the seared vegetables.

Nutrition (per serving)

Calories:510 kcal
Protein:17 g
Carbs:72 g
Fat:19 g

Directions

  1. 1
    Sliced red onion pickling in lime juice

    Combine the red onion, 2 tablespoons lime juice, sugar, and 1/4 teaspoon salt in a small bowl. Massage gently with clean fingers and set aside, stirring once or twice while the fajitas cook.

  2. 2
    Lime sour cream whisked in a ceramic bowl

    Whisk the sour cream with the remaining 1 tablespoon lime juice, water, and a pinch of salt until smooth and spoonable. Refrigerate until serving.

  3. 3
    Fajita spice blend beside sliced portobello mushrooms

    Stir together the cumin, smoked paprika, oregano, garlic powder, and remaining salt in a small dish. Pat the sliced mushrooms dry so they brown instead of steaming.

  4. 4
    Portobello mushrooms browning in a cast-iron skillet

    Heat a large cast-iron skillet over medium-high heat until a drop of water sizzles immediately. Add 1 tablespoon olive oil and half the mushrooms in a single layer; sear for 3 to 4 minutes, turning once, until deeply browned. Transfer to a plate and repeat with another tablespoon oil and the remaining mushrooms.

  5. 5
    Red and yellow peppers cooking with onion

    Add the final tablespoon oil to the skillet, then add the bell peppers and yellow onion. Cook for 6 to 7 minutes, tossing occasionally, until blistered at the edges but still slightly crisp.

  6. 6
    Mushrooms, peppers, and black beans in the skillet

    Return the mushrooms to the skillet. Add the black beans and spice mixture, then toss for 2 minutes until the spices smell fragrant and the beans are hot. Add 1 tablespoon water and scrape up the browned bits; remove from the heat.

  7. 7
    Flour tortilla warming beside a covered stack

    Warm the tortillas one at a time in a dry skillet for about 20 seconds per side, or wrap the stack in damp paper towels and microwave until pliable. Keep covered in a clean towel.

  8. 8
    Open fajitas topped with avocado, onion, and lime crema

    Fill each warm tortilla with the mushroom mixture. Top with drained pickled onion, avocado, cilantro, and lime crema, then serve immediately with lime wedges.

Ingredients

  • Red Onion, Thinly Sliced:1/2 small
  • Fresh Lime Juice:3 tbsp
  • Granulated Sugar:1 tsp
  • Kosher Salt:1 tsp
  • Sour Cream:1/2 cup
  • Water:1 tbsp
  • Ground Cumin:1 1/2 tsp
  • Smoked Paprika:1 tsp
  • Dried Oregano:1 tsp
  • Garlic Powder:1/2 tsp
  • Portobello Mushrooms, Stems Removed and Sliced:12 oz
  • Red Bell Pepper, Sliced:1 large
  • Yellow Bell Pepper, Sliced:1 large
  • Yellow Onion, Sliced:1 medium
  • Olive Oil:3 tbsp
  • Black Beans, Drained and Rinsed:15 oz can
  • Small Flour Tortillas:8
  • Avocado, Sliced:1 large
  • Fresh Cilantro Leaves:1/2 cup
  • Lime, Cut Into Wedges:1

Tips & Notes

  • Do not crowd the mushrooms; cooking them in two batches is the key to browned edges.
  • For a vegan version, replace the sour cream with an unsweetened plant-based alternative.
  • The pickled onion and lime crema can be prepared up to one day ahead and refrigerated separately.