In a bowl, combine olive oil, chopped garlic, lemon zest, lemon juice, paprika, and fresh parsley. Mix well.
Season your Spanish fish inside and out with salt and pepper.
Generously apply the marinade mix into the slits and inside the cavity of the Spanish fish.
Let the Spanish fish marinate for at least 30 minutes. The longer you marinate, the more flavorful your fish becomes!
Preheat your grill or oven to medium-high heat.
Place the marinated Spanish fish on the grill/oven. Add the thinly sliced bell peppers alongside.
Cook the Spanish fish for about 8-10 minutes on each side or until the flesh easily flakes off with a fork.
Once fully cooked, remove the Spanish fish from the grill/oven and let it rest for 5 minutes before serving.