Prepare the steak: Dissolve the bouillon cube in 3/4 cup hot water in a bowl; set aside to cool. Whisk in 2 tablespoons olive oil, the soy sauce, Worcestershire sauce, lemon juice, 1 teaspoon salt and 1/2 teaspoon pepper. Place the steak in a large resealable plastic bag, pour in the marinade and seal, squeezing out the air. Refrigerate for at least 4 hours or up to 1 day.
Prepare the herb butter: Mix the butter with the chives, parsley, chervil, a pinch of salt, 1/2 teaspoon pepper and the lemon juice in a bowl.
About 30 minutes before cooking, remove the meat from the bag (discard the marinade), dry it well and bring to room temperature. Heat a large heavy skillet over high heat, about 2 minutes. Rub the steak with the remaining 1 tablespoon olive oil. Sprinkle 1 tablespoon salt over the surface of the pan; add the meat and set a heavy skillet on top to weigh it down. Sear for about 7 minutes; turn the steak, replace the weight and cook until a thermometer inserted into the side reads 110 degrees for medium-rare, about 5 minutes.
Transfer the steak to a cutting board; brush with some of the herb butter, tent with foil and let rest for about 10 minutes. Thinly slice against the grain; top with more herb butter and drizzle with the pan juices.