Balsamic-Glazed Portobello Burgers
Portobello burgers are a tasty meatless alternative at a cookout. The rich mushroom flavor is enhanced by the tangy blue cheese and the sweet caramelized onions.
- 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
Preparation:
Brush any dirt from the mushroom caps and remove the stems.
Place the balsamic vinegar in a small saucepan and bring to a boil over medium-high heat. Reduce the heat and simmer, stirring occasionally, until the vinegar is reduced by 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 make the caramelized onions.
Separate the onions into rounds. Heat the oil in a large skillet over medium-low heat. Add the onions, cover the pan and cook for 12 to 15 minutes, stirring 3 or 4 times during the process. Remove the cover, raise the heat to medium and add 1/2 teaspoon salt and a pinch of sugar. Continue cooking, uncovered, for 20 to 30 minutes, stirring frequently and loosening any browned bits that may accumulate on the bottom of the pan. If the onions are sticking to the pan, try adding a little water, one or two tablespoons at a time. The onions should turn a deep golden brown color and have an almost marmalade-like consistency.
Preheat a gas or charcoal grill to a medium temperature (about 400°F). Oil the grates, add the mushrooms, gill side up, and grill for 3 minutes, then turn them over, brush with the rest of the balsamic reduction and grill until tender, 3 to 4 minutes longer. Transfer to sandwich rolls and top with caramelized onions and blue cheese. Serve immediately.
Makes 6 servings
