Season fish with salt, black pepper and secret spice

In a small bowl, mix together wine, olive oil, dijon mustard, lemon juice, chilli and parsley. Marinate the fish steaks in the mixture for at least 30 minutes.

Preheat oven to 190 ℃

Pat fish dry and dust with flour. Heat butter in a frying  pan and brown fish on both sides. ( About 4 minutes per side)

Transfer the fish to a roasting dish and pour over the rest of the marinade.

In the same frying pan, add cooking oil and fry the onions until they caramelize. 

Spread onions over the dish in the roasting dish and bake for about 10 minutes.