Chinese Chili

Ingredients

• 1 teaspoon vegetable oil
• 2 pounds pork shoulder, cubed
• 1 pound boneless beef round steak, cubed
• 2 large green bell peppers, chopped
• 2 large onions, chopped
• 2 small stalks celery, diced
• 4 cups beef broth
• 1 (8 ounce) can sliced bamboo shoots, drained
• 1 (8 ounce) can sliced water chestnuts, drained
• 1 teaspoon ground black pepper
• 2 tablespoons chili powder, or to taste
• 1/2 cup soy sauce
• 3 tablespoons cornstarch
• 8 sliced fresh mushrooms
• 1 cup fresh bean sprouts