Season the steak. Pat the steak dry. Mix salt, pepper, smoked paprika, garlic powder, and onion powder.
Rub all over both sides. Let it rest at room temperature for 20–30 minutes. This helps it cook evenly.
Make the avocado ranch. In a blender or food processor, add avocado, Greek yogurt, buttermilk, mayo, lime juice, garlic, dill/parsley, chives, salt, and pepper.
Blend until smooth and creamy. Adjust with more buttermilk to thin, or more lime and salt to taste.
Prep the salad base. Add mixed greens to a large bowl. Scatter on tomatoes, cucumber, red onion, corn, and herbs.
Keep the crunchy toppings and cheese aside for now.
Sear the steak. Heat a cast-iron skillet or grill over medium-high until very hot. Add oil, then the steak. Sear 3–4 minutes per side for medium-rare (thicker cuts may need a minute or two more).
You’re looking for a deep brown crust.
Rest and slice. Transfer steak to a cutting board and rest 5–10 minutes. Slice thinly against the grain so the pieces stay tender.
Dress the greens lightly. Toss the salad base with a few spoonfuls of avocado ranch to coat. You want a light sheen, not drenching.
Assemble. Top the dressed greens with sliced steak.
Add bacon, pepitas, and cheese. Drizzle a bit more dressing over the steak. Finish with a squeeze of lime and a pinch of salt over the tomatoes to make flavors pop.
Serve. Plate immediately while the steak is still slightly warm.
Pass extra dressing on the side.