To make chimichurri, whisk with a fork to combine garlic, lemon juice, red wine vinegar, and sea salt. Whisking vigorously for a minute or two, add herbs, and then olive oil. Taste, and add sea salt as needed. Set aside while you prepare salad.

Set a large, heavy bottomed skillet or grill pan over medium-high heat. Brush sourdough with olive oil on both side and sprinkle with sea salt. Toast bread in the hot skillet until crisp and golden, 3 - 4 minutes a side. Set aside to cool then cut into triangles.

Cool skillet briefly and wipe out any crumbs. Set heat to high.

Sprinkle steaks on both sides with sea salt and place on hot skillet. Cook steak 3 - 5 minutes per side, or until the meat has reached an internal temperature of 150 degrees F for medium (we usually cook steaks to medium rare, but find that medium is better in a salad). Remove steaks from heat; rest 8-10 minutes. Slice steak against the grain into 1/2-inch thick pieces, spoon on a generous amount of chimichurri, and carefully set sliced steak on salad.

Place kale and radicchio in a large bowl and toss with several tablespoons chimichurri and maybe a pinch of sea salt. Tuck crouton triangles into the side of salad, and finish with chive blossom petals and a few twists of freshly ground pepper. Serve immediately.