I Cant Believe There Is No Meat Bolognese

• 1 tbsp extra virgin olive oil
• 1 brown onion, finely chopped
• 2 garlic cloves, crushed
• 2 celery stalks, finely chopped
• 2 carrots, grated
• 700 ml passata
• 1 tbsp thyme
• 1 cup red lentils, dried
• 500 g wholemeal spaghetti