Tuna Salad Niçoise

• 4 free range eggs
• 400 g tin tuna in oil, drained
• 1 iceberg lettuce
• 0.5 red onion, sliced thinly
• 1 punnet of cherry tomatoes, sliced into quarters
• 1 cup sugar snap peas, ends trimmed
• 800 g butter beans, rinsed and drained
• 4 anchovy fillets (optional)
• 2 tbsp capers (or use 1/4 cup of olives if you prefer)
• 0.5 cup extra-virgin olive oil
• 4 tbsp red wine vinegar
• 1 clove garlic (crushed)
• 2 tsp dijon mustard