In a large bowl, combine tofu with tamari, balsamic vinegar, and Worcestershire sauce. Marinate for 15-20 minutes.
In a skillet, add oil, marinated tofu, and serrano pepper. Sauté for 8-10 minutes on medium-high heat, tossing until lightly browned. Let cool.
Place tofu in a large bowl, add remaining ingredients (except for bread), and stir to combine. Spread on bread.
Notes: Bell pepper may be substituted with ¾ cup cucumber (seeded and diced).