Begin by preparing your ingredients: Cut the mullet into 1cm cubes and place into a mixing bowl. Immediately place the bowl back into the fridge or over ice to keep chilled while you prepare everything else.
Cut the cherry tomatoes into 1/8ths. Remove the pit from the olives and cut into a small dice. Mince the chives and finely slice the mint. Set these up on a small tray or plate to make life easier when you come to season the fish.
Place your bread under the grill or in the toaster and cook until golden brown. Allow to cool slightly while you prepare your tartare.
Still in the mixing bowl, season the fish well with roughly 2 tablespoons of extra virgin olive oil and a good pinch of salt. Stir to combine until the fish is evenly seasoned and has a nice shine to it.
Add most of your tomatoes, olives and herbs. Zest half of the lemon over the mixture and add a teaspoon or so of sumac and a quarter teaspoon of chili flake.
Squeeze the juice from a quarter of the lemon and stir to combine.
Taste and add more of each ingredient based on your tastes. You can always add more, but without adding more chopped fish it’s going to be hard to dilute any flavours you went overboard with.
To finish, top your toast with plenty of the tartare. Finish with a final drizzling of extra virgin olive oil and a light sprinkling of sumac.