For the mustard sauce: Whisk all ingredients together in a small bowl. Set aside.
Season the steaks. We like to use Montreal Steak Seasoning, or simply use salt and pepper. Or for a real treat, try one of our favorite pepper blends, Savory Spicy Whiskey Barrel Smoked Black Pepper.
Heat grill to 500 degrees, then turn down the heat to 350.
Place steaks on the hot grates and cook, turning once. Cook until a meat thermometer registers 135 degrees for medium rare (recommended) 150 degrees for medium.
Notes
Don't have an outdoor grill? You most certainly can cook this steak indoors. Use a heavy skillet like a cast iron, or a French Carbon Steel Pan. A grill pan is also a good choice here. Which ever pan you choose, get the pan nice and hot. Add a couple tablespoons butter or canola oil and place the seasoned ribeye steaks into the hot pan. Cook about 5 minutes per side or until cooked to desired doneness. You can also briefly sear them well on both sides and finish in a 375 degree oven. Again, use a digital read thermometer to determine doneness.Presentation Tip: Transfer the spicy mustard sauce to a squeeze bottle and squeeE dots of increasing size on each plate. Arrange sliced steak and grilled new red potatoes on the plates. Garnish with scallions or chives.