Discard the outer leaves of the red cabbage and cut out the root. Chop into small strips, then mix together with 2 tablespoons of olive oil, salt, pepper, and 2 tablespoons of cider vinegar. Set aside in the fridge for 20 minutes.
Remove the skin from the cucumber, cut it lengthwise into 4 pieces and remove the seeds. Then chop into small cubes. Peel and finely chop the red onion.
Add finely chopped dill, salt, pepper, and olive oil to the sour cream.
Finely chop the coriander.
Lightly season the char with salt and pepper and drizzle with lemon juice. Heat olive oil in a griddle pan and cook the char on both sides on a high heat. Remove the fish and set it aside to rest a while.
Cook the char skin side down first. This helps to seal in the juices.
Brush the tortillas lightly with olive oil, grill for 30 seconds on each side and begin to assemble.
Place the cabbage, onion, cucumber, and coriander onto the tortilla.
Flake the char with a fork or similar. Set aside the skin.
Pile the flaked char on top of the other ingredients, drizzle the dill over the top, fold the tortilla in half, and serve.