Spicy salmon mixed-grain sushi

Ingredients

• 1/2 cup (100g) brown rice
• 1/4 cup (50g) tri-colour quinoa
• 1/4 cup (50g) pearl barley
• 2 cups (500ml) water
• 1/4 cup (60ml) rice vinegar
• 2 tablespoons caster (superfine) sugar
• 1/2 teaspoon sea salt flakes
• 1/4 cup (35g) sunflower seeds, chopped finely
• 2 sheets toasted seaweed (nori)
• 200 grams sashimi-grade salmon, sliced thinly
• 1/2 teaspoon chilli powder
• 1 medium avocado (250g), sliced thinly
• 1 teaspoon lemon juice
• Picked cucumber
• 2 lebanese cucumbers (260g), peeled, sliced thinly
• 2 tablespoons rice vinegar
• 1 tablespoon caster (superfine) sugar
• 1 clove garlic, sliced thinly