Heat your oven to 180°C (350°F).
In an ovenproof pan, heat a little olive oil over medium heat. Add the chopped red onion and sauté for 5 minutes, until softened.
Stir in the garlic and cook for 1 minute. Add the frozen peas and the wine (or stock), stirring until the liquid starts to reduce slightly.
Place the sea bass fillets on top of the pea mixture. Scatter the prawns around them. Season generously with sweet paprika, salt, and pepper.
Cover the pan with a lid or foil and bake for 10 minutes, or until the sea bass is opaque and flakes gently. Avoid overcooking.
If using, sprinkle chopped fresh herbs (such as mint, dill, basil, or parsley) over the top before serving.
Serve with mashed potatoes, sweet potato mash, or quinoa for a light but satisfying meal.