In frying pan, cook oil and crushed peppercorns on low heat 7-10 minutes until bubbles appear. Allow to cool then add salt and rub this into the steaks. Allow to stand 1 hour.
For the blue cheese butter, mix butter, blue cheese, salt, and minced onion together. Set aside.
Heat oven to 220°C/450°F and put in a baking sheet to heat.
Heat extra oil in frying pan on medium heat and cook the steaks on the first side for four minutes, then flip and cook on second side for three minutes.
Transfer to baking sheet and roast for five minutes, spread on prepared butter, and allow to stand for five minutes.