Begin with making the chimichurri. In a food processor, add the fresh herbs, garlic, lemon zest and juice and olive oil and blend until well combined and no large leaves are left over.
Add 2-3 tablespoons to the room temperature butter and use a spoon to mix everything together.
Add salt and pepper and taste for seasoning. You can also add more Chimichurri to the butter if you prefer, or serve the rest of the herb sauce on the side as well.
Once butter is done, transfer compound butter to plastic wrap and roll into a log shape and refrigerate until ready to use.
Once ready remove steak from refrigerator for at least 10 minutes, get your grill on high heat.
Season steak liberally all over with salt and pepper. Drizzle some oil and sear steak for 6-8 minutes until good char marks form. Flip steak over and grill for another 6-8 minutes and cook until desired temperature.
With thick steaks, cover with foil or Weber lid to cook the centre. With a meat thermometer, cook until it reaches internal temperature of 550 – 600C for medium-rare.
Once done, remove steak to a cutting board and allow to rest for at least 10 minutes. Cut into slices and serve with Chimichurri butter.