Baked fish with dried prawns, onions & mushroom

I found a couple of baked fish recipes and this recipe gave a surprising nice taste. I adapted it and did it this way ....

Ingredients:
One sea bass 500 gm (washed and gutted)

Marinade fish with .....
2 tbsp oyster sauce
1 tbsp sesame oil
1 tbsp chinese cooking oil
1 tbsp sugar
1 tbsp cooking oil

Fry together in 3 tbsp of cooking oil......till fragrant.....
1 large yellow onion (sliced)
3 handful of dried shrimps (softened & chopped)
1 tsp Szechuan peppercorn
10 pieces shitake mushrooms (cut into halves)

Put the fried mixture on top and below the marinaded fish in a baking casserole. Cover with aluminium foil. Bake in a preheated oven at 200 degree C for 30 mins.