Slice the vegetables. In a small dish, combine all taco spice mix ingredients.
Drain and add corn to a frying pan with a small drizzle of oil. Cook on medium heat until browned, about 10 minutes. Remove from pan and set aside.
Add pepper and onion to a pan and soften, about 5 minutes (add more oil if needed). Remove from pan and set aside.
Add cooked black beans, taco spice mix and lime juice to the pan and stir until evenly coated. Heat until liquid is gone and beans are warm.
To assemble the tacos, place peppers, onions, corn and beans on a tortilla. Top with avocado slices, fresh cilantro and your favourite salsa.