Prepare the marinade by whisking the ingredients together in a small bowl. Gently pull the oyster mushrooms into bite-size pieces. Slice the shiitake tops and discard the stems. In a medium bowl, combine the mushrooms with the cilantro, red onion, cucumber and tomatoes. Combine with 5 tablespoons of the marinade and gently toss until everything is well coated. Marinate in the fridge for 4–6 hours. Sprinkle with additional cilantro and top with root chips; serve.