For the pickled mushrooms
- Place a pot over high heat and add the sugar, the vinegar, the coriander, the chili flakes, salt, and let the mixture come to a boil.
- Cut the mushrooms into large pieces, add them to the pot, and mix. Remove the pot from the heat and transfer the mixture to a bowl. Cover with plastic wrap and refrigerate for 6-8 hours. The plastic wrap should be touching the surface of the mixture so that the mushrooms will stay submerged.
- If you want your mushrooms to be softer and not crunchy, then once you add the mushrooms to the pot, boil them for 2-3 minutes and follow the rest of the process.
- Drain and set aside.
For the mushroom tempura
- Place a frying pan with the seed oil over medium heat.
- In a bowl add the flour, 40 g corn starch, salt, the club soda, and whisk well until there is a batter.
- Sprinkle the rest of the corn starch over the mushrooms and mix. Add the mushrooms into the batter and fry them in batches, for 2-3 minutes, until they are crispy and golden.
- In a bowl add the cherry tomatoes cut in half, the spring onions finely chopped, the stems of the coriander finely chopped, and the soy sauce. Mix and set aside.
- Spread the spinach tortillas on your working surface and divide the yogurt, the mushrooms, and the cherry tomato salsa among them, and then wrap.
- Serve with the coriander leaves.