Vegetable Stock Recipe | The Dinner Ladies

Ingredients

• 1 tablespoon olive oil
• 2 medium onions, unpeeled, cut into 2cm pieces
• 5 celery stalks (including the leaves) cut into 2cm pieces
• 3 large carrots, peeled, cut into 2cm pieces
• 200g button mushrooms
• 1 small fennel bulb, cut into 2 cm pieces
• 1 head of garlic, halved
• 1 teaspoon of sea salt
• 6 sprigs flat-leaf parsley
• 1 bay leaf
• 3 sprigs thyme
• 1 teaspoon whole black peppercorns
• 4 litres water