The Portobello Burger narrow display The Portobello Burger wide display

The Portobello Burger

Roasted tomato, fontina, and salad


Active Time:
~10 min
Total Time:
~20 min

About this Recipe

For this veggie burger, Chef Travis wanted to use a whole ingredient instead of a processed patty. Portobellos are packed with concentrated mushroom flavor, and the roasted tomato adds even more umami that will leave you ready for more.



Prep portobellos & onion

  • Remove stems from portobellos and scrape out gills with a spoon. Wipe away any soil from mushroom caps with a damp paper towel.
  • Place mushrooms, stemmed side up, in Zones 2 and 3 of Brava glass tray.
  • Peel red onion and cut two ¼-inch-thick slices.
  • Place onion slices in Zone 1 of Brava glass tray.
  • Finely dice 1 tablespoon of remaining onion and set aside for vinaigrette. You will have some onion left over.


Prep vinaigrette & tomato

  • In small bowl, combine sherry vinegar, ½ teaspoon Dijon mustard, diced onion, ¼ cup extra-virgin olive oil and a pinch of salt and pepper; stir well. Save remaining mustard for serving.
  • Pour 1½ teaspoons vinaigrette into each mushroom cavity. Save remaining vinaigrette for salad.
  • Season mushrooms with a pinch of salt.
  • Cut two ½-inch-thick slices of beefsteak tomato. You will have some tomato left over.
  • Place tomato slices in Zone 1 of glass tray next to onion.
  • Drizzle tomato and onion slices with 1 teaspoon cooking oil and season with a pinch of salt.


Slide glass tray into top shelf

  • Select “Portobello Burger” on your Brava touchscreen and follow instructions.
  • While food cooks, arrange buns, cut side up, on Brava metal tray.
  • Next, prepare salad.


Make salad

  • Cut cherry tomatoes in half.
  • In large bowl, toss together spring lettuce mix, cherry tomatoes and pumpkin seeds.


Warm buns

  • When your food is done, remove glass tray from Brava, immediately slide metal tray into top shelf and close door. The residual heat will warm buns.


Assemble burgers, dress salad & serve

  • Place a slice of roasted tomato and onion inside each mushroom cavity, then top with a slice of fontina.
  • When fontina has melted (about 1 minute), remove buns from Brava.
  • If desired, spread remaining Dijon mustard on buns.
  • Place a mushroom on each bottom bun and cover with top buns.
  • Season salad with a pinch of salt and pepper, then toss with remaining vinaigrette to taste. You may have some vinaigrette left over.
  • Divide salad between individual plates and add burgers.