(Optional) If time allows, let the steak rest at room temperature for 20 minutes.
Season both sides of the steak generously with salt and black pepper.
Heat up a skillet over medium high heat until very hot, about 4-5 minutes.
Add olive oil to the skillet and sear the steak for 2-3 minutes untouched.
Flip the steak and sear an additional 2-3 minutes.
In the last 1-2 minutes of cooking, add the butter and rosemary. Use a spoon to baste the steak in the herby melted butter for 1 minute.
Remove the steak from heat to rest 5 minutes before slicing into bite-sized strips.
Prep the salad base, by adding a generous serving of the baby crispy green leaf lettuce to each serving bowl. Add the halved tomatoes, thinly sliced red onion, and avocado.
Top with the sliced steak, crispy smashed potatoes, garnish with fresh cilantro, and then drizzle with classic ranch to enjoy!