Slice the king oyster mushrooms and zucchini, then slice the tomatoes and chop the cilantro.

Heat the frying pan over high heat and add the sliced king oyster mushrooms.

Press the mushrooms with the heavy pan to release their moisture, then cook until the released liquid evaporates.

Add half the cooking oil, paprika, garlic powder, and salt to the mushrooms, then stir to coat.

Add the balsamic vinegar and sugar, then fry the mushrooms until deeply browned and caramelized.

Heat the remaining cooking oil in the frying pan and add the sliced zucchini.

Fry the zucchini until browned and tender, then season it with salt and dried Italian herbs.

Combine the vegan mayo, tomato paste, agave syrup, white wine vinegar, roasted curry powder, and salt in the mixing bowl.

Whisk the curried mayo until smooth, then taste and adjust the salt if needed.

Season the sliced tomatoes with salt and let them stand briefly to draw out excess moisture.

Spread the curried mayo over the bread, then layer with lettuce and salted tomatoes.

Add the caramelized mushrooms, browned zucchini, and cilantro, then close each sandwich with the remaining bread.