- 2 1 1/3-pound racks of lamb, well trimmed
- 2 medium red onions, cut through root ends into 1/2-inch-thick wedges
- 1/4 cup frozen orange juice concentrate
- 1 1/2 tablespoons minced peeled fresh ginger
- 1 tablespoon chili-garlic sauce
- 3/4 teaspoon Chinese five-spice powder or ground aniseed
Preheat oven to 450°F. Brush large rimmed baking sheet with olive oil. Place lamb racks in center of baking sheet. Arrange onion wedges around lamb. Brush lamb and onion wedges with olive oil. Whisk hoisin, orange juice concentrate, minced ginger, chili-garlic sauce, and Chinese five-spice powder in small bowl to blend. Brush hoisin glaze generously over lamb and onion wedges; sprinkle with salt and generous amount of pepper.
Roast until instant-read thermometer inserted into lamb registers 130°F for medium-rare, about 25 minutes. Transfer lamb racks to plate. Continue roasting onion wedges until tender, about 5 minutes longer. Divide onion wedges among plates. Cut lamb racks into chops; place lamb atop onion wedges and serve.