Pre-heat the oven to 200°C.
Prepare the filling by heating the olive oil in a medium saucepan over a medium-high heat. Saute the garlic and onion with a little seasoning for 6-7 minutes, stirring occasionally, until they start to soften. Add this point, add the chill pepper, yellow pepper, celery and stir well, continuing to cook for 8-10 minutes until they are soft.
Stir in the sherry vinegar, mango chutney and sugar and season well. Remove from the heat and set to one side.
Rub the cod fillets with the sunflower oil and season well. Transfer to the lined baking sheet and bake in the oven for 9-11 minutes until just cooked; firm yet springy to the touch and just opaque.
Lay the tortillas on a flat surface and top with lettuce leaves. Spoon over some of the prepared pimento sauce. Arrange a finger of cod on top of the lettuce and transfer to serving plate.
Garnish with more of the sauce, some lettuce leaves, sprigs of coriander and a whole red chilli.