Umami is the Japanese term for deliciousness. The umami flavor in certain foods comes from glutamic acid, an amino acid associated with savory or meaty flavors. Mushrooms contain a significant amount of glutamic acid and are considered an umami-rich food. Other umami-rich foods include tomatoes, aged cheeses like Parmeggiano Reggiano, and fermented foods like fish sauce and soy sauce. This recipe aggregates a number of umami-rich foods to create a savory, meat-free sandwich.
Portabella Sandwiches with Umami Sauce

Recipe courtesy of The Culinary Institute of America
Serves 4
Ingredients:
- For umami sauce
- ¼ cup mayonnaise
- 1 ½ teaspoons reduced sodium or “lite” soy sauce
- ½ teaspoon Dijon-style mustard
- For caramelized onions
- 1 medium white or yellow onion, sliced
- 1 tablespoon extra virgin olive oil
- ½ teaspoon dried thyme
- For portabella mushrooms
- 4 large portabella mushroom caps, stems removed
- 1 tablespoon extra virgin olive oil
- 3 teaspoons reduced sodium or “lite” soy sauce
- 3 teaspoons balsamic vinegar
- 4 whole grain rolls, toasted or warmed on the grill
Preparation:
- Preheat your grill to medium-high.
- In a small bowl combine the mayonnaise, soy sauce, and mustard. Set aside
- In a medium sauté pan over medium-high heat combine the onions and olive oil. Cook for 10 to 12 minutes, or until onions are brown and have developed caramelized flavor. Add the thyme, cook for additional 30 seconds, remove from heat, and set aside
- Brush the portabella mushroom caps with olive oil on both sides. Grill 3 to 4 minutes per side, or until tender.
- Assemble your sandwiches by placing a mushroom cap on the bottom of each bun. Top the mushroom with about ¼ cup caramelized onions and 1 tablespoon of the umami sauce. Place the top bun on each sandwich and serve.