Steak and spuds with salsa verde

Ingredients

• 1 1/2 tablespoon olive oil
• 500 gram small kipfler potatoes, halved lengthways
• 8 100g beef fillet medallions
• 1 bunch watercress (350g) trimmed
• Salsa verde
• 1 clove garlic, crushed
• 1 teaspoon dijon mustard
• 2 teaspoon baby capers
• 2 anchovy fillets
• 3 teaspoon red wine vinegar
• 3 cornichons
• 1/4 cup loosely packed fresh mint leaves
• 1/4 cup loosely packed fresh basil leaves
• 2 tablespoon coarsely chopped fresh flat-leaf parsley
• 1/4 cup (60ml) extra virgin olive oil