Grilled chicken avocado sandwich - Australian Avocados

Ingredients

• 2 avocados, thinly sliced
• 3 chicken thigh fillets
• 1 tsp garlic powder
• 1 tbsp lemon juice
• large pinch of salt and black pepper
• 1 tbsp olive oil
• ¼ cup thinly sliced celery
• 1 spring onion, finely sliced, green only
• 1 tbsp chopped fresh chives
• 3 tbsp mayonnaise
• 2 tbsp wholegrain mustard
• 1 tsp chilli flakes (optional)
• 1 cup salad sprouts (alfalfa or radish)
• Focaccia bread