With their firm, almost meaty texture, portobello mushrooms make a wonderful stand-in for burgers. For a heartier meal, top the cooked mushrooms with a slice of reduced-fat cheese or soy cheese and grilled, sliced red onions.
MEAL PLAN: Prepare a quick pasta salad with cooked macaroni, diced tomatoes, a handful of chopped basil and some pitted kalamata olives. Toss with a low-fat vinaigrette dressing. Season to taste with salt and pepper and serve at room temperature.
Prepare grill or heat grill pan over medium-high heat. Hold 1 mushroom stemmed side up in your hand. Using a sharp paring knife, carefully cut and scrape to remove most of dark brown “gills.” Repeat with remaining mushrooms. Set aside.
Drain roasted peppers in strainer set over bowl; reserve liquid. You should have about 2 tablespoons liquid. Thinly slice peppers; set aside. Whisk vinegar, oil, mustard and 1 tablespoon water into roasted pepper liquid in bowl to make dressing. Place 1 tablespoon dressing in medium bowl and reserve.
Brush remaining dressing over both sides of mushrooms. Place mushrooms stemmed side down on grill or in pan. Cook until juicy and tender, turning once, about 7 minutes.
Place 1 mushroom on bottom half of each bun. Top with pepper slices. Add arugula to reserved dressing in bowl and toss well to coat. Divide arugula salad among mushrooms, cover with bun tops and serve.