- Strip the parsley leaves from the stems; coarsely chop the leaves. Set aside half for garnish.
- Pat the steaks dry with a paper towel; season generously with salt and pepper.
Top sirloins and filet mignons:
In a large frying pan over medium-high heat, warm 1 to 2 tablespoons oil until hot but not smoking. Add the steaks and cook, turning frequently, until well browned but still rare, 5 to 6 minutes for top sirloins and 7 to 10 minutes for filet mignons. Add the bagna càuda, half the parsley, and 1 tablespoon [2 TBL] ghee or butter (from your pantry), if using, and cook, spooning the sauce over the steaks, until fragrant and warmed through and the steaks are medium-rare, 1 to 2 minutes. Remove from the heat.
Rib-eyes:
In a large frying pan over high heat, warm 1 to 2 tablespoons oil until hot but not smoking. Add the steaks and cook, turning once, until starting to brown, about 1 minute per side. Add the bagna càuda, half the parsley, and 1 tablespoon [2 TBL] ghee or butter (from your pantry), if using, and cook, spooning the sauce over the steaks, until fragrant and warmed through and the steaks are medium-rare, 1 to 2 minutes. Remove from the heat.
Transfer the steaks to a cutting board to rest for 5 minutes, then cut into ½-inch-thick slices. Season the bagna càuda to taste with salt and pepper; set aside in the pan for serving.
While the steaks cook and rest, start preparing the vegetables.