Credit: Recipe courtesy of the American Lamb Board The National Culinary Review, May 2016
1 (1-1¼ lb.) American lamb top round ½ cup prepared balsamic dressing 1 t. Dijon-style mustard ½ t. coarse ground pepper 24 medium portobello mushrooms, stems removed ¼ cup + 2 T. olive oil, divided ¼ cup balsamic vinegar 1 large red onion, thinly sliced 48 thin roasted red bell pepper strips, 2 inches long 24 petite rolls, sliced 24 frill picks
Trim all visible fat off lamb. Place in plastic bag. In bowl, blend dressing, mustard and pepper. Pour into bag; seal, rotate meat to coat. Refrigerate at least 4 hours to marinate. Remove lamb from marinade (discard marinade). Place lamb on roasting rack in pan. Roast in 325°F oven 50-60 minutes or until desired degree of doneness. Remove from oven; cover, let stand 10 minutes. Thinly slice. Cover; refrigerate.
Place mushrooms on baking sheet. In small bowl, whisk together ¼ cup olive oil and vinegar. Brush all sides and centers of mushrooms with mixture. Bake in 375°F oven 15 minutes. Remove; cool.
In large skillet, heat remaining 2 T. olive oil over medium-high heat. Add onion made into rings; saute 6-8 minutes until lightly browned. Cool; set aside.
Place 1 mushroom on base of roll; add 2 bell pepper strips. Top with sliced lamb and a few onion rings. Secure top of bun to sandwich with frilly pick.
24 (appetizer) servings