Porterhouse is a loin cut of beef that combines tenderloin and strip steak on either side of the bone — think T-bone, but larger and ideal for sharing. In this bistro-inspired steak frites recipe, the porterhouse is seared in a cast-iron skillet, finished in the oven and served with crispy twice-fried potatoes and a rich anchovy-parsley butter.

What is a Porterhouse Steak?

A porterhouse is cut from the rear of the short loin and contains both strip steak and tenderloin separated by a T-shaped bone. It’s similar to a T-bone steak but has a larger portion of tenderloin, making it particularly good for sharing.

A sliced steak on a black plate with fries and sauce on the side.

Porterhouse Steak Frites With Anchovy-Parsley Butter

A bistro-style porterhouse steak with crispy twice-fried potatoes and savoury anchovy-parsley butter.

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Ingredients

1 kg waxy potatoes peeled and cut into strips
2 L sunflower oil for frying
1 kg porterhouse steak at room temperature
sea salt for seasoning
splash olive oil
¼ cup butter
2 cloves garlic peeled and crushed
pepper for seasoning

Anchovy-Parsley Butter

7 tbsp butter
6 anchovies
⅓ cup finely chopped parsley

Instructions

Pat dry potato strips. In Dutch oven, heat sunflower oil over medium-low heat until deep-fryer thermometer reads 265°F. Deep-fry half of the potatoes for about 10 minutes or until cooked but not brown. Remove from pan with slotted spoon and set on paper-towel-lined tray. Repeat with remaining potatoes.

Anchovy-Parsley Butter

In saucepan, heat butter over medium heat until it starts to brown and smells nutty, 3 to 4 minutes. Add anchovies and break with wooden spoon until they almost fall apart. Add chopped parsley and cook for 1 more minute. Set aside.
Heat oven to 375°F. Season steak on both sides with salt. Heat cast-iron skillet or heavy oven-safe frying pan over medium-high heat, add oil and butter and heat until foamy and smoking. Add steak and garlic and don’t move steak for 2 to 4 minutes. Lift corner of steak to check for a deep-brown crust before turning over. Flip and cook for a maximum of 4 minutes for a 2-to-2 1⁄2-inch-thick steak.
Cook in oven until medium-rare. Remove and place steak on serving platter; cover loosely with aluminum foil. Let rest for 5 minutes.
Heat anchovy butter over low heat.
Reheat oil over medium heat to 375°F and cook fries a second time until crispy, 4 to 5 minutes. Transfer to paper-towel-lined tray; season with salt while hot.
Cut steak into thick slices; season with pepper and top with anchovy-parsley butter.

Keyword anchovy butter, cast iron steak, french fries, porterhouse steak, porterhouse steak recipe, steak frites

Tips for Cooking Porterhouse Steak in a Cast-Iron Skillet

Bring the steak to room temperature : Take the porterhouse out of the refrigerator before cooking so the thick steak cooks more evenly.
Use a very hot cast-iron skillet: Heat the skillet over medium-high heat, then add the oil and butter. You want the pan hot enough that the butter is foamy and the fat is beginning to smoke before the steak goes in.
Don’t move the steak too soon: Once the porterhouse hits the skillet, leave it alone for 2 to 4 minutes. Lift a corner to check for a deep-brown crust before flipping.
Let it rest before slicing : Transfer the steak to a platter, loosely cover it with foil and rest for 5 minutes before cutting it into thick slices.
Season with pepper after cooking : This recipe seasons the steak with salt before searing, then adds freshly ground pepper after the steak has rested and been sliced.

Why Anchovy Butter Works With Steak

Anchovies bring saltiness and deep savoury flavour to the butter without making it taste overtly fishy – think of the role they play in a classic Caesar salad. It’s a classic French approach: anchovies have long been paired with butter, herbs and beef to add umami and sharpen rich flavours. Here, the anchovies melt into browned butter, while fresh parsley adds freshness and cuts through the richness of the porterhouse.