Vietnamese "Banh Mi" Chicken Burger

INGREDIENTS

• 1 1/2 teaspoon apple cider vinegar
• 6 ounces firm tofu
• 2 teaspoons sesame oil
• 1/4 cup scallions, chopped
• 1 cup bean sprouts
• 1 cup white vinegar
• 2 1/2 teaspoon salt, divided
• 1 medium carrot, peeled and sliced into ribbons
• 1/2 pound shiitake mushrooms
• 1 small cucumber, thinly sliced
• 4 whole-wheat hamburger buns
• 1/2 teaspoon black pepper, divided
• 1 bunch cilantro, chopped
• 1/4 teaspoon ground cumin
• 1/8 teaspoon brown sugar
• 2 teaspoons soy sauce
• 1 tablespoon olive oil
• 1 teaspoon sugar
• 3 radishes, thinly sliced
• 1 egg
• 1 1/4 pounds ground chicken