Portobello Tostadas with Avocado Crema & Tomato Salsa

Vegetarian portobello tostadas featuring charred, grilled mushrooms, onions & bell peppers, plus homemade salsa & avocado crema. Bring on grilling season!
I love warm spring weather – I can always count on my husband, Matt, to get amped up for grilling season. Lately, with recommendations to stay home, there have been countless meals to prepare over the last few months. The grilling season is especially welcome this year as we get to experience a change of scenery, if even just out into to our own backyard. Enter: portobello tostadas!

Weber’s Time to Grill by Jamie Purviance is a cookbook we rely on time and again for reliable grilling recipes. The seasoning and flavors are so well thought out and most of the recipes include details on how to round out the meal with a tasty side. It was a gift to my husband for his first Father’s Day. This year marks my brother’s first Father’s Day (yes, I’m an aunt!), so I thought it would be a great gift for his birthday in early June. Meat lovers and vegetarians alike will be blown away by this one! It’s bursting with so many of my favorite flavors… slightly charred peppers & red onions, homemade pico de gallo with plenty of jalepeno, and lime crema. Portobello tostadas are really the best thing I’ve eaten in a long time.
Portobello Tostadas with Avocado Crema & Tomato Salsa ingredients
-serves 4-
Crema:
1 ripe avocado, diced
½ cup sour cream or whole milk plain yogurt
2 Tablespoons fresh lime juice
Kosher salt to taste
Salsa:
1 cup finely chopped ripe tomato
¼ cup thinly minced red onion
1 small jalepeno, minced
2 tablespoons finely chopped cilantro
1 tablespoon red wine vinegar
Santa Fe Spice Rub:
- 1 ½ teaspoons kosher salt
- 1 teaspoon ground black pepper
- 1 teaspoon cumin
- ½ teaspoon ancho chili powder
- 1 teaspoon light brown sugar
- ½ teaspoon dried oregano
- (or substitute 2 Tablespoons fajita seasoning)
Mushrooms & Peppers:
4 large portobello mushrooms, stems and gills removed
1 large red onion, cut crosswise into ½ inch slices
extra virgin olive oil
2 large bell peppers, 1 red and 1 yellow, seeded and cut into fourths
8 flour tortillas (8-inch preferable)
2 cups grated Monterey jack cheese
How to make portobello tostadas
- Blend all crema ingredients in a food processor until smooth. Season with salt to taste before refrigerating until ready to serve.
- Mix all salsa ingredients in a medium bowl and season with salt. Set aside at room temperature.
- Prepare the grill for direct cooking over medium heat (350-450 degrees F).
- Generously brush the mushroom caps, onion slices and pepper pieces with oil and season evenly with the Santa Fe seasoning.
- Brush the cooking grates clean. Grill the mushrooms, onions, and peppers over direct medium heat, with the lid closed as much as possible, until browned and tender, turning occasionally. The mushrooms will take 12 to 15 minutes, the onion will take 8-10 minutes, and the bell pepper will take 6 to 8 minutes. If necessary, to prevent the mushrooms from drying out, occasionally brush them with a bit more oil. Remove the vegetables from the grill and scrape off any blackened areas of the peppers. Cut the vegetables into thin strips.
- Grill the tortillas on one side over direct medium heat, with the lid open, just until warm, 10 to 20 seconds. Turn them over, top each one with ¼ cup of cheese and grill just until the cheese melts. Remove from the grill and assemble the tostados with the grilled vegetables, salsa and crema.
Recipe adapted from: Weber’s Time to Grill by Jamie Purviance
Mixing it up
- Make this dairy free with the addition of an extra avocado instead of the sour cream or yogurt in the “crema” and by removing the Monterey jack cheese or using dairy-free cheese.
- This could be made gluten-free using corn tortillas instead of flour tortillas.

More delicious vegetarian dinner ideas
Portobello Tostadas with Avocado Crema and Tomato Salsa
Ingredients
Avocado Crema
- 1 ripe avocado, diced
- 1/2 cup sour cream or whole milk plain yogurt
- 2 tbsp freshly squeezed lime juice
- kosher salt, to taste
Homemade Salsa
- 1 cup ripe tomato finely chopped
- 1/4 cup red onion thinly minced
- 2 tbsp cilantro finely chopped
- 1 small jalepeno minced
- 1 tbsp red wine vinegar
Santa Fe Spice Rub
- 1 1/2 tsp kosher salt
- 1 tsp ground black pepper
- 1 tsp ground cumin
- 1 tsp light brown sugar
- 1/2 tsp ancho chili powder
- 1/2 tsp dried oregano
Mushrooms & Peppers
- 4 large portobello mushrooms stems and gills removed
- 1 large red onion cut crosswise into 1/2 inch slices
- extra virgin olive oil
- 2 large bell peppers, one red and one yellow seeded and cut into fourths
- 8 flour tortillas 8-inch preferable
- 2 cups monterey jack cheese grated
Instructions
- Blend all crema ingredients in a food processor until smooth. Season with salt to taste before refrigerating until ready to serve.
- Mix all salsa ingredients in a medium bowl and season with salt. Set aside at room temperature.
- Prepare the grill for direct cooking over medium heat (350-450 degrees F).
- Generously brush the mushroom caps, onion slices and pepper pieces with oil and season evenly with the Santa Fe seasoning.
- Brush the cooking grates clean. Grill the mushrooms, onions, and peppers over direct medium heat, with the lid closed as much as possible, until browned and tender, turning occasionally. The mushrooms will take 12 to 15 minutes, the onion will take 8-10 minutes, and the bell pepper will take 6 to 8 minutes. If necessary, to prevent the mushrooms from drying out, occasionally brush them with a bit more oil. Remove the vegetables from the grill and scrape off any blackened areas of the peppers. Cut the vegetables into thin strips.
- Grill the tortillas on one side over direct medium heat, with the lid open, just until warm, 10 to 20 seconds. Turn them over, top each one with ¼ cup of cheese and grill just until the cheese melts. Remove from the grill and assemble the tostados with the grilled vegetables, salsa and crema.
Notes
- Go dairy-free with the addition of an extra avocado instead of the sour cream or yogurt in the “crema” and by removing the Monterey jack cheese.
- This could be made gluten-free using corn tortillas instead of flour tortillas.
- Recipe adapted from: Weber’s Time to Grill by Jamie Purviance
Yum, i’m Going to try this!
Let me know how it turns out!
Looks delicious!!
Thanks, Jeannene! Hope you get a chance to give it a try.
Delicious! Will definitely be making again.
I’m so glad!
The rub and the crema are both delicious, and the texture of the portobello mushrooms is a nice change to meats traditionally used in Mexican dishes. Will definitely make again!
Yay! I’m so glad you liked it! :0)