Freefrom Mushroom soup with (or without) smoked mackerel

Ingredients

• 1 heaped tbsp coconut oil or 2 tbps olive oil
• 3 medium leeks, sliced very finely
• 4 anchovies, chopped small
• 350g open cap mushrooms
• 1 large baking potato, scrubbed and sliced thickly
• 1.5 litres gluten and wheat free vegetable stock
• 1 level tbsp coconut oil or 1 tbsp olive oil
• sea salt and freshly ground black pepper
• 1 fillet peppered smoked mackerel (optional)