Step 1

Mix all the marinade ingredients in a large bowl. Add the cleaned mushrooms and coat them in the marinade. Set aside to marinate for at least an hour, giving the mushrooms a stir every 15 minutes or so to make sure they are absorbing the marinade evenly.

Step 2

Heat up the oven to 160° C / 320° F fan function (or 180° C / 355° F without fan) and if you have a wire rack-topped oven tray use that, otherwise line a regular oven tray with a piece of baking paper.

Step 3

Arrange the marinated mushrooms on a wire rack-topped oven tray, leaving plenty of space around each so that they can crisp up easily. Bake for about 20 minutes, until cooked through and charred in places.

Step 4

Julienne the carrot and cucumber (discarding the watery centre) using a julienne peeler. Cut the radishes into matchsticks and slice the sushi ginger thinly.

Step 5

Place the prepped veggies in a sterilised (rinsed with boiling water) jar.

Step 6

Put the rice vinegar, ½ cup / 120 ml water (more water if you want the pickles to be less sharp), sugar (adjust the amount to taste) and salt in a small pot and bring to the boil. Continue simmering for about 10 minutes.

Step 7

Pour hot pickling liquid over the raw vegetables. Once the pickling liquid cools down, keep the jar in the fridge.

Step 8

Toast your bread or bread rolls if you wish.

Step 9

Spread a layer of ripe avocado at the bottom of each sandwich, top with fresh spinach, grilled (and cooled off) mushrooms, drained pickles, coriander and Sriracha mayo. Close the sandwich and enjoy.