Portobello Bruschetta with Rosemary Aïoli

Preparation Preheat oven to 375°F. Mix vinegar, honey, brown sugar and thyme in medium bowl. Transfer 1/2 cup marinade to small bowl; set aside. Place mushrooms in 15x10-inch glass baking dish. Pour remaining marinade over mushrooms. Cover baking dish with foil and bake until mushrooms are tender, about 40 minutes. Transfer mushrooms to work surface; cool. Cut mushrooms into 1/2-inch-wide slices. Heat 2 tablespoons oil in heavy large skillet over medium heat. Add red onions and sauté until very tender and beginning to brown, about 25 minutes. Pour in reserved 1/2 cup marinade and cook until liquid is absorbed and onions are glazed, about 6 minutes. Set onions aside. Char bell peppers over gas flame or in broiler until blackened on all sides. Enclose in paper bag and let stand 10 minutes. Peel, seed and chop peppers. Place peppers in medium bowl. Add green onion, basil, garlic and 1 tablespoon oil and toss to combine. (Mushrooms, onion mixture and bell pepper mixture can be prepared 1 day ahead. Cover separately and refrigerate.) Preheat oven to 375°F. Place bread slices on baking sheet. Brush bread with additional olive oil. Bake until lightly toasted, about 10 minutes. Layer portobello mushroom slices, arugula, onions and then bell pepper mixture atop bread slices. Bake until heated through, about 3 minutes. Season to taste with salt and pepper. Drizzle bruschetta with Rosemary Aioli. Serve immediately.

Preparation Preheat oven to 375°F. Mix vinegar, honey, brown sugar and thyme in medium bowl. Transfer 1/2 cup marinade to small bowl; set aside. Place mushrooms in 15x10-inch glass baking dish. Pour remaining marinade over mushrooms. Cover baking dish with foil and bake until mushrooms are tender, about 40 minutes. Transfer mushrooms to work surface; cool. Cut mushrooms into 1/2-inch-wide slices. Heat 2 tablespoons oil in heavy large skillet over medium heat. Add red onions and sauté until very tender and beginning to brown, about 25 minutes. Pour in reserved 1/2 cup marinade and cook until liquid is absorbed and onions are glazed, about 6 minutes. Set onions aside. Char bell peppers over gas flame or in broiler until blackened on all sides. Enclose in paper bag and let stand 10 minutes. Peel, seed and chop peppers. Place peppers in medium bowl. Add green onion, basil, garlic and 1 tablespoon oil and toss to combine. (Mushrooms, onion mixture and bell pepper mixture can be prepared 1 day ahead. Cover separately and refrigerate.) Preheat oven to 375°F. Place bread slices on baking sheet. Brush bread with additional olive oil. Bake until lightly toasted, about 10 minutes. Layer portobello mushroom slices, arugula, onions and then bell pepper mixture atop bread slices. Bake until heated through, about 3 minutes. Season to taste with salt and pepper. Drizzle bruschetta with Rosemary Aioli. Serve immediately.