Creamy avocados are a terrific match with juicy grilled steak. You can marinate the meat ahead (and it's all the better if you do), but don't assemble the salad until just before serving to keep the avocado from turning brown.
Reserve a cup of whole cilantro leaves; finely chop the rest. Transfer chopped leaves to a medium bowl.2.
Reserve a cup of whole parsley leaves; finely chop the rest. Transfer chopped parsley to the bowl with the cilantro. Add scallions, jalapeno, garlic, salt, and lemon juice. Stir in oil. Taste and add more salt and/or lemon juice if needed.3.
Scatter the cilantro and parsley leaves over 4 serving plates. Fan the avocados out on top and sprinkle lightly with fine salt to taste.4.
Spoon the herb sauce over the avocado, making sure to include the oil in the bowl. Top with sliced steak and sprinkle with capers. Sprinkle with flaky sea salt and black pepper to taste and serve immediately.