Make the chimichurri and set it aside. You can make it up to a day in advance.
Mix the olive oil, cumin, oregano, paprika, salt and pepper in a small bowl until combined.
Trim the steaks, if needed, cutting the 2 steaks apart along the silver skin which connects them.
Rub the spice blend all over the steaks, top them with sliced onions and garlic, and pop them in the fridge to marinate for at least 2 hours or overnight.
Preheat your gas grill to high or prep your charcoal grill for direct heat.
Grill the steaks over high heat for 3-4 minutes per side or until the internal temperature reaches 125-F on a digital meat thermometer.
Let the steak rest for 10 minutes before slicing.
Slice and serve!
Notes
Chef Jenn's Tips
Don't throw out the onions from the marinade - grill them or cook them up in a skillet! Yum!
Add a pinch of crushed red pepper flakes to the spice rub if you'd like a bit of heat.
Don't overcook this meat - it cooks fast and is best eaten med-rare or medium, but no higher.
Control your heat - getting a good sear on this steak means lots of flavor but there is oil in the spice rub so watch for flare-ups.
Nutritional information for this recipe is provided as a courtesy and is calculated based on available online ingredient information. It is only an approximate value. The accuracy of the nutritional information for any recipe on this site cannot be guaranteed.