Pressure-Cooked Country Lamb and Barley Stew

Ingredients

• 2 tablespoon plain (all-purpose) flour
• 1 kilogram boned lamb leg, chopped coarsely
• 1 tablespoon olive oil
• 8 (200g) baby brown onions
• 2 cup (500ml) chicken stock
• 2/3 cup (130g) pearl barley
• 3 sprigs fresh thyme
• 2 (300g) stalks celery, trimmed, chopped coarsely
• 2 medium_piece (240g) carrots, chopped coarsely
• 400 gram baby new potatoes, quartered