Mackerel Tartare Toasts

This is an utter joy to eat.  Tender, flavourful and pretty healthy (if you ignore that tiny bit of cream...) - ensure that you get *very* fresh mackerel that is suitable for eating raw from a trustworthy fishmonger.

It really couldn't be easier.  Just make it.  Go on.  Trust me.

• 2 mackerel (filleted, pinboned, skinned and cut into very small pieces)
• juice half a lime
• 1 teaspoon horseradish sauce
• 2 teaspoons double cream
• 1/2 spring onion (finely sliced)
• 1/2 teaspoon freshly chopped flat-leaf parsley
• 1/2 teaspoon freshly chopped dill
• salt and pepper (for seasoning)
• 1/4 small baguette (very thinly sliced)
• 1/4 cucumber (very thinly sliced)