Preparation
Heat 2 tablespoons oil in a large skillet over medium 
heat. Add mushrooms, onion and bell pepper. Cook, stirring occasionally,
 until pepper begins to soften, 4 to 5 minutes. Add beans, paprika, 
garlic powder and black pepper. Cook, smashing beans with the back of a 
spoon, 1 to 2 minutes more. Transfer mixture to a bowl and mix in eggs, 
mustard, Worcestershire sauce and breadcrumbs. Form into 4 patties. Wipe
 out skillet; heat remaining 2 tablespoons oil over medium heat and cook
 burgers until brown and feels firm, 6 to 7 minutes each side. Place on 
buns; top with barbecue sauce, lettuce and tomato.