Preheat the oven to 200°C.
Blend butter, parsley, basil, lemon zest, pine nuts, and breadcrumbs into a paste.
Oil the swordfish steaks and sear in a hot pan for one minute per side.
Transfer the seared swordfish steaks to a baking tray.
Season the fish with salt, pepper, and lemon juice.
Spread the herb paste over the fish and roast for 10 to 12 minutes.
In a bowl, mix the mashed potatoes with butter and crushed garlic.
Fold in the chives and season with salt and pepper.
Plate the mash, top with swordfish, and pour over pan juices.
Finish with a drizzle of extra virgin olive oil.