Spanish mackerel tartare

Ingredients

• 1pc Spanish mackerel, fileted, deboned and skinned
• 1qt water
• 1 kosher salt
• 1 lemon zest
• 3 bunches of flat leaf parsley, leaves only
• 1 clove garlic
• 1pc salt cured anchovy filet, rinsed
• 1 cup extra virgin olive oil
• 1/2 cup Semolina flour
• 1/2 cup warm water
• 1tbs olive oil,plus a little more for brushing crackers
• 1tsp salt
• 1 cup flour
• 2pc jarred preserved lemon plus a little of the jarring liquid
• 1 cup Greek yoghurt
• 1tsp sugar