Tear up the mushrooms into a bowl and mix with the chipotle paste, olive oil and salt. Leave to marinade for 5 minutes.
Slice the onion into half moons, cover with salt and lemon juice and then pinch lightly until light pink.
In a hot pan, add the mushrooms and sauté for 5-10 minutes until caramelized around the edges.
In a separate pan, sauté the corn in olive oil until charred, this may take a 10-15 minutes.
Mash up the avocado and mix with the salt, lemon juice and pepper.
Warm through the tortillas and then layer everything up!
Top with vegan sour cream and enjoy with a cold can of 7Up.
