(adapted from Epicurious.com)
Makes 8-10 patties
• 1/2 cup chopped onion, divided
• 1 tablespoon olive oil plus additional for brushing
• 1/2 cup bulgur
• 1 cup water
• 1 can black beans, rinsed and drained
• ¼ cup Panko breadcrumbs, plus more to achieve desired consistency
• 1 1/2 tablespoon soy sauce
• 3/4 cup walnuts (2 1/2 ounces)
• 2 garlic cloves, coarsely chopped
• 1/2 cup packed cilantro sprigs
• 3/4 teaspoon ground cumin
• 1/4 teaspoon cayenne
• 1/4 cup soy mayonnaise (or try these yummy alternatives: raw mayo or cashew mayo)
• 1/4 teaspoon grated lime zest
• 1/2 teaspoon fresh lime juice
• 1/4 teaspoon salt
• Whole wheat buns
Cook half of onion with 1/4 teaspoon salt in oil in a small heavy saucepan over medium heat, stirring occasionally, until golden, 5 to 7 minutes. Add bulgur and water and cook, covered, over low heat until water is absorbed, 15 to 18 minutes. Transfer to a bowl and stir in beans and soy sauce.
Pulse bulgur mixture, walnuts, garlic, cilantro, cumin, cayenne, a rounded 1/4 teaspoon salt, and remaining onion in a food processor until finely chopped. Add bread crumb until the mixture is hearty enough to be formed into patties. Chill at least 10 minutes.
While patties chill, stir together soy mayonnaise, zest, and juice. Prepare grill for direct-heat cooking over medium-hot charcoal (medium heat for gas). Put perforated grill sheet on grill and preheat 10 minutes. Brush patties all over with oil. Oil grill sheet, then grill burgers on grill sheet, covered only if using a gas grill, carefully turning once, until golden brown, about 8 minutes total. Serve burgers with lime mayonnaise.