01 - Heat 1 tablespoon vegetable oil in a large skillet over medium-high heat. Add diced potatoes and season with salt, pepper, and garlic powder. Cook, stirring occasionally, 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 - Heat remaining 1 tablespoon vegetable oil in the skillet. Add shredded corned beef and sauté for 2–3 minutes until heated through and lightly crisped at edges.
04 - Heat tortillas in a dry skillet over medium heat for 30 seconds per side or microwave in a damp paper towel for 20–30 seconds until soft and pliable.
05 - Layer each warm tortilla with a portion of crispy potatoes, followed by warmed corned beef. Top generously with cabbage slaw and finish with a drizzle of sour cream.
06 - Arrange tacos on a serving platter and serve immediately while tortillas remain warm. Offer extra slaw on the side if desired.