Portobello Burgers

Ingredients

 * 7 oz jar roasted red peppers (packed in water).
 * 1 tbsp balsamic vinegar.
 * 1 tbsp olive oil.
 * 2 tsp Dijon mustard.
 * 4 large portobello mushrooms (4 to 5 inches in diameter, about 1 lb), stems and gills removed.
 * 4 whole wheat buns or hard rolls, split and lightly toasted.
 * 1 small bunch arugula, stemmed and leaves torn in half (2 cups).

Directions

 * 1) Drain roasted peppers in strainer set over small bowl, reserving liquid. You should have about 2 tablespoons liquid. Thinly slice peppers and set aside.
 * 2) Whisk vinegar, oil, mustard and 1 tablespoon water into red pepper liquid in bowl to make dressing.
 * 3) In medium bowl, place 1 tablespoon dressing and reserve.
 * 4) Prepare grill or heat grill pan over medium-high heat.
 * 5) Brush remaining dressing over both sides of mushrooms.
 * 6) On grill or pan, place mushrooms cut side down. Cook until tender, turning once, 3 to 4 minutes per side.
 * 7) Place 1 mushroom on bottom of each bun. Top with pepper slices.
 * 8) Add arugula to reserved dressing in bowl and toss well.
 * 9) Place some arugula salad on top of each mushroom, cover with bun tops and serve.