Try This Vegan Recipe For Stuffed Mushroom Burgers

Name: Try This Vegan Recipe For Stuffed Mushroom Burgers
Ingredients: 4 tomatoes; Salt and freshly ground black pepper; 1/2 teaspoon ground allspice; 1 tablespoon balsamic vinegar; 1 teaspoon brown sugar; 1 tablespoon olive oil; 4 large potatoes; 2 teaspoons Dijon mustard; 2 tablespoons oil; 1 teaspoon cider vinegar; 1 sprig rosemary; 4 tablespoons vegan butter or margarine; 1/2 onion; 4 portobello mushrooms; 1 clove garlic; 1 sprig thyme; 1 cup white breadcrumbs; 1 tablespoon red wine vinegar; 3 tablespoons pine nuts; 1/4 cup fresh flat-leaf parsley; 4 ciabatta rolls; arugula leaves