The hearty flavor and meaty texture of portobello mushrooms make them the perfect choice for a flavorful, satisfying burger. Glazed with an easy-to-make balsamic reduction and topped with sautéed onions and melted blue cheese, these burgers are delicious enough to satisfy even the most die-hard beef lover.

Balsamic-Glazed Portobello Burgers

Grilled portobello mushroom caps glazed with a balsamic reduction and topped with sautéed onions and melted blue cheese make a deliciously satisfying burger.

Author: Lynne Webb
Prep Time: 5 minutes
Cook Time: 20 minutes
Total Time: 25 minutes
Yield: 6 servings

Ingredients

6 portobello mushrooms
1/2 cup balsamic vinegar
2 tablespoons vegetable oil
2 large sweet onions, thinly sliced
Salt and freshly ground black pepper
Pinch of sugar
6 ounces crumbled blue cheese
6 soft sandwich rolls

Instructions

Brush any dirt from the mushroom caps, remove the stems and reserve them for another use.
Place the balsamic vinegar in a small saucepan and bring to a simmer over medium-high heat. Immediately reduce the heat to medium and continue cooking, stirring occasionally, until the vinegar is reduced by about half, 5 to 6 minutes. Remove from the heat and set aside to cool for 10 minutes. Use about half of the reduction to brush the tops of the mushrooms, then set them aside while you sauté the onions.
Separate the onions into rounds. Heat the oil in a large skillet over medium heat. Add the onions, season with salt, pepper and a pinch of sugar.
Sauté until the onions are soft, translucent and beginning to brown, 5 to 7 minutes.
Preheat a gas or charcoal grill to a medium temperature (about 400°F). Oil the grates, add the mushrooms, gill side up, grill for 3 minutes, then turn them over, brush with the rest of the balsamic reduction and grill until tender, about 3 minutes longer. Top each mushroom with a portion of blue cheese and cook just until the cheese begins to melt, 1 minute more.
To serve, place a portion of onions on the bottom of each bun, add a cheese-topped portobello and serve immediately.