Pat the halibut filets dry and let sit at room temperature for 30 minutes.
Meanwhile, combine the parsley, chives, and jalapeno in a mixing bowl. Peel and segment the grapefruit, adding 2 tablespoons of the juice to the herbs and reserving the segments separately. Stir in the red wine vinegar and olive oil to the herb mixture. Season with a pinch of salt to taste and set aside.
Season the halibut well with a pinch of salt on all sides. Heat a large 12” stainless-steel pan over medium heat (or use 2 smaller pans). Add just enough oil to the pan to lightly coat the bottom. When the oil is hot, carefully place the halibut filets in the pan, skin-side down.
Lower the heat to medium-low and let the halibut skin slowly cook until golden and crisp. Once crisp and naturally releasing from the bottom of the pan, use a metal spatula to flip the halibut.
Continue to cook on the other side for just a few minutes until the flesh is opaque and cooked through (be careful not to overcook).
Transfer the halibut to a plate. Spoon the salsa verde over top, along with the segments of grapefruit. Serve immediately.