Add the cauliflower rice to a small pan along with a tablespoon of water. Bring to a simmer and cook for 2-3 minutes until all the liquid has evaporated. Stir in the sesame oil and tamari sauce and set aside to cool.
Carefully scoop the centre out of the cucumber discs using a teaspoon, leaving roughly a
4mm thick edge. Dice the scooped cucumber flesh and set aside.
Roughly chop the prawns and salmon and dice the pepper into small chunks.
Once the rice has completely cooled, stuff a teaspoon full into each hollowed cucumber ring.
Divide the prawns, salmon and peppers between the cucumber rings, so that they are tightly packed with filling.
Whisk together the dressing ingredients in a small bowl.
Mix the diced avocado and spring onion with the reserved diced cucumber. Stir through the fresh cilantro and add to a large serving or salad bowl.
Add the sushi filled cucumber to the bowl along with the spinach and sliced radishes.
Scatter everything with sesame seeds and drizzle with the spiced tamari dressing to serve.