fresh flat-leaf parsley
red wine vinegar
extra-virgin olive oil
sweet potatoes, cut on the diagonal into 1/4-inch-thick slices
- Heat grill to medium.
- Pulse the parsley, oregano, and garlic in a food processor until roughly chopped. Add the vinegar, oil, cayenne, and ½ teaspoon salt; pulse to combine. Set aside.
- Season the steak with the remaining salt and the pepper. Grill to desired doneness, about 4 minutes per side for medium-rare. Transfer to a cutting board; let rest 5 minutes before slicing.
- Meanwhile, toss the potatoes in a large bowl with ⅓ cup of the herb sauce.
- Place the potatoes on the grill in a single layer. Cook, turning once, until tender, about 4 minutes per side.
- Divide the steak and potatoes among plates and serve with the remaining herb sauce on the side.