Tuna Burgers

Ингредиенты

• 2 onions, thinly sliced
• 2 tbsp (30 ml) olive oil
• 1 tbsp (15 ml) red wine vinegar
• 2 avocados
• 1/2 lemon, juice only
• 1 tbsp (15 ml) olive oil
• 1 tsp (5 ml) Dijon mustard
• 1 green onion, finely chopped
• 1 lb (454 g) fresh tuna, finely chopped
• Tabasco sauce, to taste
• 4 hamburger buns
• Boston lettuce leaves
• Salt and pepper