Ingredients

  • 1/4 cup white balsamic vinegar*
  • 2 tablespoons coarse-grained Dijon mustard
  • 1 tablespoon honey
  • 1/2 teaspoon salt
  • 1/4 teaspoon coarsely ground pepper
  • 1/2 cup olive oil
  • 4 large, assorted bell peppers, cut into 2-inch-wide strips
  • 1 large red onion, thickly sliced
  • 1 (8-oz.) package baby portobello mushrooms

Method

  • Whisk together first 5 ingredients. Gradually add oil in a slow, steady stream, whisking constantly until blended. Reserve 2 Tbsp. mixture; cover and chill. Stir bell peppers and next 2 ingredients into remaining vinegar mixture. Cover and chill 30 minutes.
  • Preheat grill to 350° to 400° (medium-high) heat. Remove vegetables from vinegar mixture; discard mixture. Grill vegetables at the same time, placing peppers skin side down on cooking grate. Grill vegetables, covered with grill lid, 6 minutes or until peppers look blistered and grill marks appear. Turn all vegetables, and grill about 2 more minutes or until crisp-tender.
  • Arrange vegetables in a single layer on a serving platter. Drizzle with reserved 2 Tbsp. vinegar mixture just before serving. Season with salt and pepper to taste.
  • *White wine vinegar may be substituted.
  • Prep the vinaigrette 3 days early, and wash and cut peppers 1 day ahead.