Mark Sargeant shares the secrets behind his version of a French classic of puréed fish, potato, garlic and cream\n\n1. Add 300g potatoes , peeled and diced\n2. Add 750ml whole milk\n3. Add 100ml double cream\n4. Add 1 bay leaf\n5. Add 1 sprig thyme\n6. Add 400g smoked coley fillet (or use smoked haddock)\n7. Add extra-virgin olive oil\n8. Add 1 garlic clove , finely sliced\n9. Add 2 egg yolks\n10. Add 1 bunch spring onion , sliced\n11. Add baguette slices fried in olive oil to serve