Fish with red onions and cheese crust

1-2 tbsp cooking oil
1 medium red onion, diced
50g brown breadcrumbs
Zest and juice of lemon
150g cheese, crumbled
2 tbsp fresh chopped parsley
Salt and pepper
4 fillets sea bass or other fish of your choice, skin left on.

Fry onions in oil until transparent, add all other ingredients except fish and mix well. Preheat the oven to 180c. Divide cheese mixture into 4 and use to top unskinned sides of the fish. Place on a lightly oiled baking sheet and bake for 15-20 minutes.
Serve on crushed new potatoes into which you have stirred more cheese and chopped parsley or basil.