This recipe has a few steps and not a quick appetizer to make, but everyone loves it whether I serve it on Crostinis as here or stuff baby potatoes with it. The levels of flavors just all blend and are scrumptious together. Its worth making! —loubaby
1.Preheat oven to 375. Mix vinegar, honey, sugar and rosemary in bowl. Reserve ½ cup marinade. Place mushrooms in shallow glass baking dish. Pour marinade over mushrooms, Cover with foil and bake til tender about 40 minutes. Remove mushrooms from marinade; cool slightly and chop. (Marinade can be saved for another time in refrigerator or discard.)
2.Heat 2 Tbl oil in heavy skillet over medium heat. Add onions and cook until beginning to brown, about 25 minutes. Pour reserved ½ cup marinade over onions and cook until liquid is absorbed and onions are glazed, about 6 minutes. Add chopped mushrooms and mix lightly.Can be prepared 1 day in advance in the refrigerator; bring to room temperature before serving.
3.Char peppers until blackened in oven broiler or on grill; enclose in paper bag and let stand 10 minutes (or use jarred roasted peppers). Peel, seed and chop peppers. Combine peppers with shallot, basil and oil and toss. Season with salt and pepper.Can be prepared 1 day in advance in the refrigerator; bring to room temperature before serving.
Whisk all ingredients for aioli. Refrigerate ahead to blend flavors. Strain mixture in a small mesh strainer before placing in a plastic squeeze bottle. Just use a spoon if you don't have a squeeze bottle and you don't need to strain.
4.Be sure to have your toppings at room temperature if not warm. You can warm them in the microwave. Preheat oven to 375. Place bread slices on baking sheet. Bake until lightly toasted, about 10 minutes. Brush lightly with olive oil. Layer mushroom & onion mixture on Bruschetta; top with pepper mixture. Drizzle Bruschetta with a squirt of Rosemary Aioli.