01 - Heat 1 tablespoon oil in a large skillet over medium-high heat. Add diced potatoes and season with salt, pepper, and garlic powder. Cook stirring frequently until golden and crisp, approximately 12–15 minutes. Remove from skillet and set aside.
02 - In a mixing bowl, combine shredded cabbage, grated carrot, green onions, parsley, mayonnaise, Dijon mustard, apple cider vinegar, salt, and pepper. Toss thoroughly until all vegetables are evenly coated. Set aside to allow flavors to meld.
03 - Add remaining oil to the skillet. Place shredded corned beef in pan and sauté for 2–3 minutes until heated through and lightly crisped at edges.
04 - Warm flour tortillas in a dry skillet over medium heat for 30 seconds per side or microwave in batches of 2 for 20 seconds until soft and pliable.
05 - Build each taco by placing a layer of crispy potatoes on the warm tortilla, followed by a portion of corned beef. Top generously with cabbage slaw and finish with a drizzle of sour cream.
06 - Arrange assembled tacos on a serving platter and serve immediately. Offer extra slaw on the side for guests who prefer additional crunch.