Dry the steaks well and season generously with salt. Heat a large cast iron pan over medium-high heat. When hot, add a tablespoon of avocado oil. When the oil is hot, add the steak. Sear the steak over high heat, about 3-5 minutes per side and cook to desired doneness. To determine doneness, insert a thermometer into the thickest part of the steak and be sure to pull them off the heat a few degrees below desired final temperature as they will continue to cook via carryover cooking. Cook to 130ºF for rare, 135ºF for medium-rare, or 145ºF for medium. Remove the steak to a cutting board and let rest 10 minutes. Do not clean the pan.

While the steak rests, sear the asparagus in the now empty pan over medium high heat, about 5 minutes. The outsides should be very lightly charred. Add a bit of water to the pan to steam them to desired doneness, about 2-5 minutes more depending on how thick they are. You want tender-crisp finish to them. Season with a bit of salt and set aside.

Stir together the Dijon and lemon juice. Pour the avocado oil in slowly while whisking to incorporate the oil fully and form an emulsion. Stir in the tarragon and then season to taste with salt and fresh ground black pepper.

Combine the mixed greens, tomatoes, and asparagus in a bowl. Drizzle with half the dressing and toss to coat evenly. Divide the mixture between two plates and then slice the steak thin against the grain. Lay across the salad and drizzle with remaining dressing. Garnish with a bit more fresh tarragon, if desired.