Marinated mackerel with green olive & celery dressing - Good Food Middle East

Ingredients

• 2 mackerel, filleted and pin bones removed
• ½ tsp fennel seeds, toasted
• 150ml olive oil
• 3 banana shallots, sliced into rings
• 1 ½ tbsp golden caster sugar
• juice ½ lemon
• 150ml red wine vinegar
• 10 green olives, pitted and halved
• 2 celery sticks, thinly sliced at an angle
• 1 tsp chopped celery leaves
• lemon wedges, to serve
• crème fraîche, to serve (optional)