Petite Lamb Sandwiches with Mushrooms & Onions - Catelli Brothers

Ingredients

• 1 Catelli Brothers American Lamb top round (1-1 1/4 pounds)
• 1/2 cup prepared balsamic dressing
• 1 teaspoon Dijon-style mustard
• 1/2 teaspoon coarse ground pepper
• 24 medium Portobello mushrooms, stems removed
• 1/4 cup plus 2 tablespoons olive oil
• 1/4 cup balsamic vinegar
• 1 large red onion, thinly sliced
• 48 thin roasted red bell pepper strips, 2” long
• 24 petite rolls, sliced
• 24 decorative picks