The combination of a dry rub and basting the beef while grilling creates a blackened outside with a juicy, delicious inside. The fresh and tangy chimichurri sauce is a wonderful accompaniment.
Combine salt, pepper, garlic powder, parprika, onion powder, rosemary, and cayenne pepper in small bowl.
Place the beef roast on a sheet pan, cover lightly with sunflower oil, and coat on all sides with the the spice blend.
Cover with plastic wrap and refridgerate for at least 4 hours.
Make the Chimichurri Sauce
Chop, dice, and mince the garlic, herbs, and shallot and add to a small bowl. Add the salt, pepper, and red pepper flakes. Add the red wine vinegar and lemon juice. Whisk in the olive oil and mix well to combine all the ingredients. Let stand for at least 30 minutes before serving. If serving later, store in the fridge and bring it to room temperature before serving.
Make the Basting Sauce
After 4 hours, remove the beef from the refrigerator and let come to room temperature for 30 minutes.
During this time, combine in a small mixing bowl, the vinegar, sunflower oil, crushed garlic, and Dijon mustard. Mix well.
Grilling the Beef
Preheat the grill to high and lightly oil the grates.
Once heated, place the beef on the grill and brush with the basting sauce. Cook beef for 5 minutes, flip, baste, and then repeat the flipping and basting every 5 minutes, for a total of 25-30 minutes or until the internal temperature reahces 130 degrees. (use an probe thermometer to check temp)
Remove from the grill and let rest at least 10 minutes before slicing.
Serving and Storage
Cut the beef into slice and eat right away, or portion in containers and freeze up to two months.