For the steak: preheat a grill over MEDIUM-HIGH heat. Season strip steak with salt and pepper, then cook to medium rare—about 4 minutes on each side. Allow to rest for 5 minutes before slicing very thin.
For the pickled vegetables: Combine carrot, daikon and bell pepper in a small saucepan and top with rice wine vinegar. Cook on LOW heat for 30 minutes. Remove from pot and refrigerate until ready to use
To serve: Toast the baguette halves until slightly crisped, about 1 minute. Spread the liver pâté evenly on the bottom halves. Divide the sliced steak between the bread bottoms. Place 3 slices of the cheese over it. Add the sorrel, cilantro, pickled vegetables and jalapeños. Spread the mayonnaise on the cut sides of the top buns. Season with salt and pepper and put on the bun tops. Serve.