Start by making the creamy vegan tzatziki. In a bowl, combine vegan yogurt with grated cucumber, minced garlic, lemon juice, and a pinch of salt. Mix well until smooth and creamy, then set aside in the refrigerator to chill.

Drain the canned chickpeas, reserving a couple of tablespoons of their juice. Transfer them to a microwave-safe bowl and add water. Microwave for 30 seconds until warm.

Using a fork or a potato masher, mash the warmed chickpeas until creamy but still with some chunks. Mix in tahini, lemon juice, turmeric, smoked paprika, salt, garlic powder, cumin, and scallions. Adjust consistency with reserved juice or water.

Slice toppings—Roma tomatoes, cucumber, and avocado—into thin slices. If desired, toast the bread until golden and crispy.

On one slice of toasted bread, spread a layer of mashed avocado. Layer the chickpea mixture, followed by sliced tomatoes, cucumbers, and pickled red onions. Top with the second slice of bread.

Slice the sandwich in half for easy handling. Serve immediately with your favorite side.