01 -
Get a big bowl ready with ice water. Peel your potatoes and cut them into fry-shaped sticks about ⅓-inch thick—if you've got a mandolin with a ⅜-inch setting, that works great too. Drop the cut potatoes into the ice water and let them hang out for 15 minutes. This helps remove excess starch for crispier fries. When time's up, drain them well and pat them completely dry with paper towels.
02 -
Clip a deep-fry thermometer to a large, heavy-bottomed pot and pour in your peanut oil. Heat it over medium-high until it hits 300°F. Working in smaller batches so you don't crowd the pot, carefully lower the potatoes into the hot oil. Let them cook for 3 to 4 minutes—they should start getting tender but shouldn't be browning yet. Use a slotted spoon to transfer them to a baking sheet lined with paper towels.
03 -
While the fries are doing their thing, crank the heat to high under a large skillet. Blot your steak dry with paper towels and sprinkle the salt all over it. Add the olive oil to your hot skillet—wait until it's just starting to smoke. Lay the steak in carefully and let it sear for 4 to 6 minutes per side for a nice medium-rare. Move the cooked steak to a cutting board, place those butter pats right on top, and let it rest for 5 to 10 minutes. This is crucial for keeping all those juices in.
04 -
Bump up your oil temperature to 350°F. Time for the second fry—this is where the magic happens. Again working in batches, drop those par-cooked potatoes back into the hot oil. Fry them for about 5 minutes until they turn a gorgeous golden brown and get super crispy. Transfer to your paper towel-lined sheet and immediately hit them with salt and freshly cracked black pepper.
05 -
Slice your rested steak thinly against the grain—this keeps it tender. Arrange the steak slices on plates alongside those crispy golden fries and serve with garlic aioli for dipping.