Pound salsa verde ingredients in a pestle and mortar until a thick paste forms.
Preheat the grill to high.
Mix softened butter with garlic and parsley, then season with salt and pepper.
Remove mushroom stalks, fill with garlic butter, and top with breadcrumbs.
Grill mushrooms for 4-6 minutes until cooked through.
Heat a griddle pan, rub steaks with oil, season, and sear for 2-3 minutes per side.
Cover steaks and let them rest in a warm place for five minutes.
Heat deep-fat fryer oil to 180°C.
Fry frozen chips in batches for 4-5 minutes until golden-brown.
Drain chips on kitchen roll and season with salt.
Serve steaks topped with salsa verde alongside the chips and mushrooms.