Melt the butter and olive oil in a large frying pan until it sizzles.
Put the trout - skin (or skinned) side down - and fry for 1 minute.
Flip and fry for about 4 minutes.
Turn and fry again for 4 minutes.
Turn once more and fry for a further minute until the fish is cooked and hot.
Remove the fish, keep it warm and add the glass of wine, capers and chopped parsley to the pan.
Scrape the residue from the frying pan and stir the mixture thoroughly.
Pour the sizzling juices over the fish and serve with some new potatoes and buttered veg or a salad.