Wine Pairing: Rex Goliath Cabernet Sauvignon
Preheat: oven to 400°F and adjust oven rack to upper middle position.
Bake Potatoes: Bake potatoes on sheet pan until skin is crisp and deep brown, about 1 hour. Remove from oven; transfer potatoes to cooling rack and let sit until cool enough to handle, about 10 minutes.
Prepare Potatoes: Using an oven mitt or folded kitchen towel to handle warm potatoes, cut each potato in half, lengthwise. With a spoon, scoop flesh from each half into medium bowl, leaving a 1/8" to 1/4" thickness of flesh in each shell. Arrange shells on lined sheet pan and return to oven until dry and slightly crisped, about 10 minutes. Remove shells and set aside. Increase oven setting to broil.
Filling: Heat butter in sauté pan over medium heat. Add onion and scallions and sauté until soft, 3 minutes. Reserve for later. Mash potato flesh with fork or meat pounder until smooth. Stir in sautéed onions, scallions, cheddar, sour cream, buttermilk, chipotle, cilantro, salt, pepper and lemon juice until well combined. Spoon mixture into crisped shells, mounding slightly at the center; return to oven. Broil until spotty brown and crisp on top, 10 to 15 minutes. Serve warm.