Mix 4 cloves minced garlic, 4 tablespoons olive oil, 5 tablespoons red wine vinegar, 1 teaspoon brown sugar, 1 teaspoon Italian seasoning, ¼ teaspoon each salt and pepper, and ¼ teaspoon red pepper flakes in a small bowl. Combine completely using a fork or whisk.
Place 3 pounds boneless chuck steak in a cake pan or flat-bottom pan. Pour the chuck steak marinade over the steaks and toss until completely coated.Place plastic wrap over the top of the pan and place in the refrigerator for 24 hours. Do not skip this step! Marinating the chuck steak is what allows it to be so tender and delicious after cooking.
Place 1 stick of room temperature unsalted butter in a small bowl. Add 2 cloves minced garlic, 1 tablespoon chopped fresh rosemary, and 1 tablespoon chopped fresh thyme to the butter. Stir with a fork or hand mixer to combine.Scrape the compound butter onto a piece of plastic wrap and roll it into a log.Pinch the ends of the plastic wrap together to hold the butter in shape.Place the butter log in the fridge and allow it to harden while the steak marinates.
Heat a charcoal or gas grill. Place your marinated steaks on the grill over direct heat. Grill for 3-4 minutes per side.Move the steaks to indirect heat, cover, and continue to grill until they reach your desired level of doneness. Use a grilling thermometer to check the temperature and see our chart below for degree of doneness.
Remove the steaks and place a pat of compound butter on each one. Allow the steaks to rest as the butter melts.
Always use a meat thermometer for grilling for best results in getting the perfect temperature. With chuck steak, if you overcook it, it will become tough. You want a beautiful medium-rare for grilled chuck steak.