Smoky barbecued beef tacos with tomato dressing

Ingredients

• 1/4 cup (70g) salt-reduced tomato sauce
• 1/4 cup (70g) barbecue sauce
• 2 tablespoons worcestershire sauce
• 2 tablespoons mild american-style mustard
• 1 clove garlic, crushed
• 600 grams porterhouse steaks, trimmed
• 4 iceberg lettuce leaves, shredded
• 1/2 cup (60g) grated cheese
• 6 soft taco shells, heated to serve
• radish, lettuce, cucumber and avocado, chopped
• mint salsa, to serve
• Tomato dressing
• 1 large tomato
• 2 tablespoons finely chopped chives
• 1 tablespoon balsamic vinegar
• 1 tablespoon avocado or olive oil
• 1/2 small red onion, finely chopped