Prepare the ingredients by chopping the corned beef, peeling and dicing the potatoes, and shredding the cabbage.
Heat olive oil in a large skillet over medium heat. Add sliced onions and sauté until translucent.
Add shredded cabbage to the skillet with onions and cook until softened, about 5-7 minutes.
Incorporate the chopped corned beef into the skillet and let it warm through.
Boil the diced potatoes in a separate pot until tender, then drain.
Add the boiled potatoes to the skillet and mix everything. Season with salt and pepper to taste.
Warm the flour tortillas in a dry skillet for about 30 seconds on each side.
Assemble the tacos by placing the filling in the center of each tortilla and folding it over.