Tuna and Avocado Salad with Fermented Onions (with Cutter)

Avocado Tuna Salad

• 1 English cucumber, halved lengthways
• 2 oz watercress
• 1 ½ oz red onions, fermented or pickled
• 8 oz avocado, diced, divided
• 2 cans tuna, packed in water, drained (5 oz ea. can)
• 2 tbsp sunflower seeds
• 3 sprigs fresh basil, leaves only
• 3 sprigs mint, fresh, leaves only
  o bien 3 sprigs parsley, leaves only
• 2 oz extra virgin olive oil
• 1 ½ oz white vinegar
• ¼ tsp salt, to taste
• ⅛ tsp freshly ground black pepper, to taste