If you are new to grilling, this is the simplest way to master grilling a steak. I prefer grilling a thicker steak so that it is well caramelized on the outside and rare to medium-rare on the inside. Because the thickness is more important than the weight, sometimes the steak is too much food for one person. I suggest splitting a steak or have one to yourself—your choice.
Ahead of time, make the Tarragon-Herb Butter: Mash or stir the butter until it is smooth and slightly fluffy. Add the tarragon, parsley, granulated garlic and salt. Mix it all together, mashing with the back of a fork to make sure all the ingredients are incorporated. Taste and adjust for seasoning.
On a piece of parchment or plastic wrap, drop the butter in spoonfuls to form a log. Roll the butter in plastic wrap and smooth it out to form a round log. Refrigerate until hard and easy to cut into pieces. This can be made in advance and stored, tightly covered in the refrigerator, for up to a week and in the freezer for up to 3 months.
Prep the asparagus: Rinse the asparagus and snap or cut off the bottoms. If desired, peel the bottom of the stalk with a vegetable peeler. Place asparagus in a re-sealable plastic bag and drizzle just enough oil in the bag to coat all the spears. Seal the bag and turn the spears to coat evenly in the bag. Sprinkle with salt, re-seal bag and turn again to evenly distribute the salt.
Heat your Spark to 500°F. Just before grilling, wrap the steaks in paper towels to remove all surface moisture. Remove paper towels and brush both sides of the steaks with olive oil and season with salt and pepper.
Place the steaks in the center of the grill grates over the heat deflector plate for about 5 minutes or until well-marked by the cooking grates. Turn the steaks and continue cooking for about 5-6 more minutes for medium rare. It will also continue to cook a little as it rests.
Remove the steaks from the grill to a platter or to dinner plates and allow to rest at least 5 minutes but no longer than 10 before serving.
Place the asparagus on the cooking grate for 3-5 minutes or until marked and caramelized. Turn the spears to grill each side; asparagus should begin to brown in spots (this indicates that the natural sugars are caramelizing) but should not char.
Remove from the asparagus from the grill and serve immediately alongside the steak. Top with the herb butter.